Contact Lenses, Hydrophilic
Parenteral Nutrition, Home
Lens Cortex, Crystalline
Paranasal Sinus Diseases
A heterogeneous family of water-soluble structural proteins found in cells of the vertebrate lens. The presence of these proteins accounts for the transparency of the lens. The family is composed of four major groups, alpha, beta, gamma, and delta, and several minor groups, which are classed on the basis of size, charge, immunological properties, and vertebrate source. Alpha, beta, and delta crystallins occur in avian and reptilian lenses, while alpha, beta, and gamma crystallins occur in all other lenses.
Abnormal immunoglobulins synthesized by atypical cells of the MONONUCLEAR PHAGOCYTE SYSTEM. Paraproteins containing only light chains lead to Bence Jones paraproteinemia, while the presence of only atypical heavy chains leads to heavy chain disease. Most of the paraproteins show themselves as an M-component (monoclonal gammopathy) in electrophoresis. Diclonal and polyclonal paraproteins are much less frequently encountered.
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
Posterior Capsule of the Lens
A class of crystallins that provides refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Beta-crystallins are similar in structure to GAMMA-CRYSTALLINS in that they both contain Greek key motifs. Beta-crystallins exist as oligomers formed from acidic (BETA-CRYSTALLIN A CHAIN) and basic (BETA-CRYSTALLIN B CHAIN) subunits.
A subclass of crystallins that provides the majority of refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Alpha-crystallins also act as molecular chaperones that bind to denatured proteins, keep them in solution and thereby maintain the translucency of the lens. The proteins exist as large oligomers that are formed from ALPHA-CRYSTALLIN A CHAIN and ALPHA-CRYSTALLIN B CHAIN subunits.
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Anterior Capsule of the Lens
A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.
A procedure for removal of the crystalline lens in cataract surgery in which an anterior capsulectomy is performed by means of a needle inserted through a small incision at the temporal limbus, allowing the lens contents to fall through the dilated pupil into the anterior chamber where they are broken up by the use of ultrasound and aspirated out of the eye through the incision. (Cline, et al., Dictionary of Visual Science, 4th ed & In Focus 1993;1(1):1)
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)
Optics and Photonics
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Phakic Intraocular Lenses
Polymers of silicone that are formed by crosslinking and treatment with amorphous silica to increase strength. They have properties similar to vulcanized natural rubber, in that they stretch under tension, retract rapidly, and fully recover to their original dimensions upon release. They are used in the encapsulation of surgical membranes and implants.
A condition characterized by recurrent episodes of daytime somnolence and lapses in consciousness (microsomnias) that may be associated with automatic behaviors and AMNESIA. CATAPLEXY; SLEEP PARALYSIS, and hypnagogic HALLUCINATIONS frequently accompany narcolepsy. The pathophysiology of this disorder includes sleep-onset rapid eye movement (REM) sleep, which normally follows stage III or IV sleep. (From Neurology 1998 Feb;50(2 Suppl 1):S2-S7)
Proto-Oncogene Proteins c-maf
Maf proto-oncogene protein is the major cellular homolog of the V-MAF ONCOGENE PROTEIN. It was the first of the mammalian MAF TRANSCRIPTION FACTORS identified, and it is induced in activated T-LYMPHOCYTES and regulates GENETIC TRANSCRIPTION of INTERLEUKIN-4. c-maf is frequently translocated to an immunoglobulin locus in MULTIPLE MYELOMA.
Paired Box Transcription Factors
Anterior Eye Segment
The measurement of curvature and shape of the anterior surface of the cornea using techniques such as keratometry, keratoscopy, photokeratoscopy, profile photography, computer-assisted image processing and videokeratography. This measurement is often applied in the fitting of contact lenses and in diagnosing corneal diseases or corneal changes including keratoconus, which occur after keratotomy and keratoplasty.
Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. (Dorland, 27th ed)
alpha-Crystallin B Chain
One of the alpha crystallin subunits. In addition to being expressed in the lens (LENS, CRYSTALLINE), alpha-crystallin B chain has been found in a variety of tissues such as HEART; BRAIN; MUSCLE; and KIDNEY. Accumulation of the protein in the brain is associated with NEURODEGENERATIVE DISEASES such as CREUTZFELDT-JAKOB SYNDROME and ALEXANDER DISEASE.
Fluorescent Antibody Technique, Indirect
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Organ Culture Techniques
A noninflammatory, usually bilateral protrusion of the cornea, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. The cause is unknown but hereditary factors may play a role. The -conus refers to the cone shape of the corneal protrusion. (From Dorland, 27th ed)
Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.
A scientific tool based on ULTRASONOGRAPHY and used not only for the observation of microstructure in metalwork but also in living tissue. In biomedical application, the acoustic propagation speed in normal and abnormal tissues can be quantified to distinguish their tissue elasticity and other properties.
Gene Expression Regulation, Developmental
An alternative to REFRACTIVE SURGICAL PROCEDURES. A therapeutic procedure for correcting REFRACTIVE ERRORS. It involves wearing CONTACT LENSES designed to force corrective changes to the curvature of the CORNEA that remain after the lenses are removed. The effect is temporary but is maintained by wearing the therapeutic lenses daily, usually during sleep.
Diagnostic Techniques, Ophthalmological
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
Electrophoresis, Polyacrylamide Gel
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
In Situ Hybridization
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The only family of the order SCANDENTIA, variously included in the order Insectivora or in the order Primates, and often in the order Microscelidea, consisting of five genera. They are TUPAIA, Ananthana (Indian tree shrew), Dendrogale (small smooth-tailed tree shrew), Urogale (Mindanao tree shrew), and Ptilocercus (pen-tailed tree shrew). The tree shrews inhabit the forest areas of eastern Asia from India and southwestern China to Borneo and the Philippines.
Maf Transcription Factors
Maf transcription factors are a family of basic-leucine zipper transcription factors that are closely related to V-MAF ONCOGENE PROTEIN. The C-MAF PROTO-ONCOGENE PROTEIN was the first mammalian Maf transcription factor identified, and now the family is known to include a variety of other Maf proteins such as MAFB TRANSCRIPTION FACTOR; MAFF TRANSCRIPTION FACTOR; MAFG TRANSCRIPTION FACTOR; and MAFK TRANSCRIPTION FACTOR.
Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions.
One of a group of nonenzymatic reactions in which aldehydes, ketones, or reducing sugars react with amino acids, peptides, or proteins. Food browning reactions, such as those that occur with cooking of meats, and also food deterioration reactions, resulting in decreased nutritional value and color changes, are attributed to this reaction type. The Maillard reaction is studied by scientists in the agriculture, food, nutrition, and carbohydrate chemistry fields.
Reverse Transcriptase Polymerase Chain Reaction
Microscopy, Electron, Scanning
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Eye Protective Devices
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Ocular Physiological Phenomena
Alice in Wonderland Syndrome
Radiation Injuries, Experimental
Chromatography, High Pressure Liquid
Intermediate Filament Proteins
Electrophoresis, Gel, Two-Dimensional
Amino Acid Sequence
Methyl-CpG-Binding Protein 2
An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.
A family of Primates of the suborder Strepsirhini containing six genera. The family is distributed in parts of Africa, India, Asia, and the Philippines. The six genera are: Arctocebus (golden potto), GALAGO (bush babies), Loris (slender loris), Nycticebus (slow loris), and Perodicticus (potto). Lorises and pottos are relatively common except for Arctocebus, the golden potto. All are arboreal and nocturnal.
Axial Length, Eye
A polyhydric alcohol with about half the sweetness of sucrose. Sorbitol occurs naturally and is also produced synthetically from glucose. It was formerly used as a diuretic and may still be used as a laxative and in irrigating solutions for some surgical procedures. It is also used in many manufacturing processes, as a pharmaceutical aid, and in several research applications.
Infectious Disease Incubation Period
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
OPPORTUNISTIC INFECTIONS with the soil fungus FUSARIUM. Typically the infection is limited to the nail plate (ONYCHOMYCOSIS). The infection can however become systemic especially in an IMMUNOCOMPROMISED HOST (e.g., NEUTROPENIA) and results in cutaneous and subcutaneous lesions, fever, KERATITIS, and pulmonary infections.
Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).
The protein components of ferritins. Apoferritins are shell-like structures containing nanocavities and ferroxidase activities. Apoferritin shells are composed of 24 subunits, heteropolymers in vertebrates and homopolymers in bacteria. In vertebrates, there are two types of subunits, light chain and heavy chain. The heavy chain contains the ferroxidase activity.
SOXB1 Transcription Factors
Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.
A group of inherited enzyme deficiencies which feature elevations of GALACTOSE in the blood. This condition may be associated with deficiencies of GALACTOKINASE; UDPGLUCOSE-HEXOSE-1-PHOSPHATE URIDYLYLTRANSFERASE; or UDPGLUCOSE 4-EPIMERASE. The classic form is caused by UDPglucose-Hexose-1-Phosphate Uridylyltransferase deficiency, and presents in infancy with FAILURE TO THRIVE; VOMITING; and INTRACRANIAL HYPERTENSION. Affected individuals also may develop MENTAL RETARDATION; JAUNDICE; hepatosplenomegaly; ovarian failure (PRIMARY OVARIAN INSUFFICIENCY); and cataracts. (From Menkes, Textbook of Child Neurology, 5th ed, pp61-3)
In Situ Nick-End Labeling
An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.
An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.
Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.
Fibroblast Growth Factors
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.
Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including NEUROPEPTIDES; CYTOSKELETAL PROTEINS; proteins from SMOOTH MUSCLE; CARDIAC MUSCLE; liver; platelets; and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 22.214.171.124.
The role of optical defocus in regulating refractive development in infant monkeys. (1/242)Early in life, the two eyes of infant primates normally grow in a coordinated manner toward the ideal refractive state. We investigated the extent to which lens-induced changes in the effective focus of the eye affected refractive development in infant rhesus monkeys. The main finding was that spectacle lenses could predictably alter the growth of one or both eyes resulting in appropriate compensating refractive changes in both the hyperopic and myopic directions. Although the effective operating range of the emmetropization process in young monkeys is somewhat limited, the results demonstrate that emmetropization in this higher primate, as in a number of other species, is an active process that is regulated by optical defocus associated with the eye's effective refractive state. (+info)
The growing eye: an autofocus system that works on very poor images. (2/242)It is unknown which retinal image features are analyzed to control axial eye growth and refractive development. On the other hand, identification of these features is fundamental for the understanding of visually acquired refractive errors. Cyclopleged chicks were individually kept in the center of a drum with only one viewing distance possible. Defocusing spectacle lenses were used to stimulate the retina with defined defocus of similar magnitude but different sign. If spatial frequency content and contrast were the only cues analyzed by the retina, all chicks should have become myopic. However, compensatory eye growth was still always in the right direction. The most likely cues for emmetropization, spatial frequency content and image contrast, do therefore not correlate with the elongation of the eye. Rather, the sign of defocus was extracted even from very poor images. (+info)
Long-term changes in retinal contrast sensitivity in chicks from frosted occluders and drugs: relations to myopia? (3/242)Experiments in animal models have shown that the retinal analyzes the image to identify the position of the plane of focus and fine-tunes the growth of the underlying sclera. It is fundamental to the understanding of the development of refractive errors to know which image features are processed. Since the position of the image plane fluctuates continuously with accommodative status and viewing distance, a meaningful control of refractive development can only occur by an averaging procedure with a long time constant. As a candidate for a retinal signal for enhanced eye growth and myopia we propose the level of contrast adaptation which varies with the average amount of defocus. Using a behavioural paradigm, we have found in chickens (1) that contrast adaptation (CA, here referred to as an increase in contrast sensitivity) occurs at low spatial frequencies (0.2 cyc/deg) already after 1.5 h of wearing frosted goggles which cause deprivation myopia, (2) that CA also occurs with negative lenses (-7.4D) and positive lenses (+6.9D) after 1.5 h, at least if accommodation is paralyzed and, (3) that CA occurs at a retinal level or has, at least, a retinal component. Furthermore, we have studied the effects of atropine and reserpine, which both suppress myopia development, on CA. Quisqualate, which causes retinal degeneration but leaves emmetropization functional, was also tested. We found that both atropine and reserpine increase contrast sensitivity to a level where no further CA could be induced by frosted goggles. Quisqualate increased only the variability of refractive development and of contrast sensitivity. Taken together, CA occurring during extended periods of defocus is a possible candidate for a retinal error signal for myopia development. However, the situation is complicated by the fact that there must be a second image processing mode generating a powerful inhibitory growth signal if the image is in front of the retina, even with poor images (Diether, S., & Schaeffel, F. (1999). (+info)
The response to prism deviations in human infants. (4/242)Previous research has suggested that infants are unable to make a corrective eye movement in response to a small base-out prism placed in front of one eye before 14-16 weeks . Three hypotheses have been proposed to explain this early inability, and each of these makes different predictions for the time of onset of a response to a larger prism. The first proposes that infants have a 'degraded sensory capacity' and so require a larger retinal disparity (difference in the position of the image on the retina of each eye) to stimulate disparity detectors . This predicts that infants might respond at an earlier age than previously reported  when tested using a larger prism. The second hypothesis proposes that infants learn to respond to larger retinal disparities through practice with small disparities . According to this theory, using a larger prism will not result in developmentally earlier responses, and may even delay the response. The third hypothesis proposes that the ability to respond to prismatic deviation depends on maturational factors indicated by the onset of stereopsis (the ability to detect depth in an image on the basis of retinal disparity cues only)  , predicting that the size of the prism is irrelevant. To differentiate between these hypotheses, we tested 192 infants ranging from 2 to 52 weeks of age using a larger prism. Results showed that 63% of infants of 5-8 weeks of age produced a corrective eye movement in response to placement of a prism in front of the eye when in the dark. Both the percentage of infants who produced a response, and the speed of the response, increased with age. These results suggest that infants can make corrective eye movements in response to large prismatic deviations before 14-16 weeks of age. This, in combination with other recent results , discounts previous hypotheses. (+info)
Recent developments in clinical photography. (5/242)A system comprising a clinical camera, specialized retractors, and a new occlusal mirror are described to maximize the quality of both intra-oral and extra-oral photography in the multi-user situation. (+info)
Effect of adaptation to telescopic spectacles on the initial human horizontal vestibuloocular reflex. (6/242)Gain of the vestibuloocular reflex (VOR) not only varies with target distance and rotational axis, but can be chronically modified in response to prolonged wearing of head-mounted magnifiers. This study examined the effect of adaptation to telescopic spectacles on the variation of the VOR with changes in target distance and yaw rotational axis for head velocity transients having peak accelerations of 2,800 and 1,000 degrees /s(2). Eye and head movements were recorded with search coils in 10 subjects who underwent whole body rotations around vertical axes that were 10 cm anterior to the eyes, centered between the eyes, between the otoliths, or 20 cm posterior to the eyes. Immediately before each rotation, subjects viewed a target 15 or 500 cm distant. Lighting was extinguished immediately before and was restored after completion of each rotation. After initial rotations, subjects wore 1.9x magnification binocular telescopic spectacles during their daily activities for at least 6 h. Test spectacles were removed and measurement rotations were repeated. Of the eight subjects tolerant of adaptation to the telescopes, six demonstrated VOR gain enhancement after adaptation, while gain in two subjects was not increased. For all subjects, the earliest VOR began 7-10 ms after onset of head rotation regardless of axis eccentricity or target distance. Regardless of adaptation, VOR gain for the proximate target exceeded that for the distant target beginning at 20 ms after onset of head rotation. Adaptation increased VOR gain as measured 90-100 ms after head rotation onset by an average of 0.12 +/- 0.02 (SE) for the higher head acceleration and 0.19 +/- 0.02 for the lower head acceleration. After adaptation, four subjects exhibited significant increases in the canal VOR gain only, whereas two subjects exhibited significant increases in both angular and linear VOR gains. The latencies of linear and early angular target distance effects on VOR gain were unaffected by adaptation. The earliest significant change in angular VOR gain in response to adaptation occurred 50 and 68 ms after onset of the 2,800 and 1,000 degrees /s(2) peak head accelerations, respectively. The latency of the adaptive increase in linear VOR gain was approximately 50 ms for the peak head acceleration of 2,800 degrees /s(2), and 100 ms for the peak head acceleration of 1,000 degrees /s(2). Thus VOR gain changes and latency were consistent with modification in the angular VOR in most subjects, and additionally in the linear VOR in a minority of subjects. (+info)
Clinical effect of low vision aids. (7/242)The number of patients with low vision is increasing as life expectancy increases. In addition, the interest and demand for low vision aids are also increasing with improved socioeconomic status and the development of mass media. Therefore, it is imperative to recognize the importance of low vision aids. We reviewed the clinical records of 118 patients who visited our low vision clinic more than twice. According to the data analyzed, optic nerve atrophy, retinal degeneration, diabetic retinopathy and age-related macular degeneration were the most common causes of low vision in these patients. The best corrected visual acuities without low vision aids were less than 0.3, but with the help of low vision aids, vision improved to more than 0.4 in 87% of the patients for near vision, and 56% for distant vision. The patients had complained that they could not read books, see a blackboard, recognize a person at a distance, and had other problems because of low vision. However, with the use of low vision aids their satisfaction with their vision rose to 70%. Hand magnifiers, high-powered spectacle lenses, and stand magnifiers were the low vision aids commonly used by people for near vision, while the Galilean telescope and Keplerian telescope were the most popular devices used for distant vision. In conclusion, low vision aids are very helpful devices to patients with low vision. (+info)
Form-deprivation myopia in monkeys is a graded phenomenon. (8/242)To shed light on the potential role of the phenomenon of form-deprivation myopia in normal refractive development, we investigated the degree of image degradation required to produce axial myopia in rhesus monkeys. Starting at about 3 weeks of age, diffuser spectacle lenses were employed to degrade the retinal image in one eye of 13 infant monkeys. The diffusers were worn continuously for periods ranging between 11 and 19 weeks. The effects of three different strengths of optical diffusers, which produced reductions in image contrast that ranged from about 0.5 to nearly 3 log units, were assessed by retinoscopy and A-scan ultrasonography. Control data were obtained from ten normal infants and three infants reared with clear, zero-powered lenses over both eyes. Eleven of the 13 treated infants developed form-deprivation myopia. Qualitatively similar results were obtained for the three diffuser groups, however, the degree of axial myopia varied directly with the degree of image degradation. Thus, form-deprivation myopia in monkeys is a graded phenomenon and can be triggered by a modest degree of chronic image degradation. (+info)
OSA | Adaptive optics optical coherence tomography angiography for morphometric analysis of choriocapillaris [Invited]
Histological studies have shown that morphometric changes at the microscopic level of choriocapillaris (CC) occur with aging and disease onset, and therefore may be sensitive biomarkers of outer retinal health. However, visualizing CC at this level in the living human eye is challenging because its microvascular is tightly interconnected and weakly reflecting. In this study, we address these challenges by developing and validating a method based on adaptive optics optical coherence tomography with angiography (AO-OCTA) that provides the necessary 3D resolution and image contrast to visualize and quantify these microscopic details. The complex network of anastomotic CC capillaries was successfully imaged in nine healthy subjects (26 to 68 years of age) and at seven retinal eccentricities across the macula. Using these images, four fundamental morphometric parameters of CC were characterized: retinal pigment epithelium-to-CC depth separation (17.5 ± 2.1 µm), capillary diameter (17.4 ± 2.3 µm), ...
Brevet US20050225501 - Self-aligned microlens array for transmissive MEMS image arrray - Google Brevets
A MEMS optical device includes a MEMS image array and a self-aligned microlens array. The MEMS image array includes a number of individual channels. The microlens array includes individual microlenses, each of which is associated with one of the channels of the MEMS image array. The microlens array is formed directly on the MEMS image array using semiconductor fabrication techniques. Each microlens is automatically aligned with its respective channel within the image array. The need for precise and expensive manual alignment of the MEMS image array and the microlens arrays is avoided. Improvements in the fill factor and the transmission efficiency of the optical device are realized. Further, by tailoring the refractive index of the lens relative to both the substrate and the ambient air, the total internal reflection phenomenon can be exploited, for additional improvement in the transmission efficiency of the optical device.
OSA | Design and fabrication of a freeform microlens array for a compact large-field-of-view compound-eye camera
with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of ...
Wavefront sensorless modal deformable mirror correction in adaptive optics: Optical coherence tomography<...
TY - JOUR. T1 - Wavefront sensorless modal deformable mirror correction in adaptive optics. T2 - Optical coherence tomography. AU - Bonora, S.. AU - Zawadzki, Robert. PY - 2013/11/15. Y1 - 2013/11/15. N2 - We present a method for optimization of optical coherence tomography images using wavefront sensorless adaptive optics. The method consists of systematic adjustment of the coefficients of a subset of the orthogonal Zernike bases and application of the resulting shapes to a deformable mirror, while optimizing using image sharpness as a merit function. We demonstrate that this technique can compensate for aberrations induced by trial lenses. Measurements of the point spread function before and after compensation demonstrate near diffraction limit imaging.. AB - We present a method for optimization of optical coherence tomography images using wavefront sensorless adaptive optics. The method consists of systematic adjustment of the coefficients of a subset of the orthogonal Zernike bases and ...
OSA | Phosphorescence lifetime based oxygen micro-sensing using a digital micromirror device
Abstract. A digital light modulation microscope (DLMM) that utilizes a digital micromirror device (DMD) on an epifluorescence microscope has been developed to modulate excitation light in spatial and temporal domains for phosphorescence lifetime detection. Local O2 concentration can be inferred through the detected lifetime around an O2-quenching phosphorescent porphyrin microsensor. Combined with microsensor arrays, the DLMM can sequentially address light to each microsensor element to construct a discrete lifetime image or O2 distribution. In contrast to conventional phosphorescence lifetime imaging, the new method eliminates the need for a pulsed light source and a time-gated camera. To demonstrate O2 sensing with lab-on-a-chip devices, an array of 150-µm-diameter micro-wells coated with phosphorescent porphyrin were observed. The locations of the sensor elements were automatically identified though image analysis. The goal of this platform is to measure the O2 consumption of individual ...
Patent US20070035847 - Method and apparatus providing graded-index microlenses - Google Patents
Microlenses are fabricated with a refractive-index gradient. The refractive-index gradient is produced in a microlens material such that the refractive index is relatively higher in the material nearest the substrate, and becomes progressively lower as the layer gets thicker. After formation of the layer with the refractive-index gradient, material is etched from the layer through a resist to form microlenses. The index of refraction can be adjusted in the microlens material by controlling oxygen and nitrogen content of the microlens materials during deposition. High-oxide material has a lower index of refraction. High-oxide material also exhibits a faster etch-rate. The etching forms the material into a lens shape. After removal of the resist, the microlenses have a lower relative refractive index at their apex, where the index of refraction preferably approaches that of the ambient surroundings. Consequently, light loss by reflection at the ambient/microlens interface is reduced.
Unique adaptive optics OCT reflection in cone inner segments of subjects with retinitis pigmentosa | IOVS | ARVO Journals
Purpose : Retinitis pigmentosa (RP) is the most common form of inherited irreversible visual loss worldwide. The biological mechanisms that cause cones to die-the most debilitating phase-remain unknown. To better describe photoreceptor loss, we used adaptive optics optical coherence tomography (AO-OCT) to characterize a subset of cones that unexpectedly present reflections from their inner segment. Methods : We used the Indiana AO-OCT system at 500 KHz A-scan rate and clinical OCT (Spectralis, Heidelberg) to image three subjects: two with early and one with late stage arRP. 450x450 μm2 AO-OCT volume videos were acquired along the temporal horizontal meridian (early stage: 2°-12° and 3°-12° retinal eccentricity; late stage: 0.5°-4.5° retinal eccentricity), which sampled the transition zone as well as the healthy and severely diseased areas that straddled it. Volumes were registered in 3D to remove eye motion artifacts, projected separately along the cone inner and outer segments (IS, OS), ...
Prediction Model of Microlens Fabricated by Modified LIGA Process
In this paper, we present a prediction model for microlens formation by means of a deep X-ray lithography followed by a thermal treatment of a PMMA (Polymethyl-methacrylate) sheet. According to this modeling, X-ray irradiation causes the decrease of molecular weight of PMMA, which in turn decreases the glass transition temperature and consequently causes a net volume increase during the thermal cycle resulting in a swollen microlens. Both a simple analysis and a Finite Element Analysis based on this model are found to be able to predict the variation pattern of the maximum heights of microlens which depends on the thermal treatment. The prediction model could be applied to optimization of microlens fabrication process.
The fabrication and characterization of plastic microlens arrays by deep lithography with protons | (2004) | Ottevaere | ...
In this paper we present the state-of-the-art of Deep Lithography with Protons (DLP), a technology that we have adopted and optimized to rapidly prototype three-dimensional micro-optical components and high-aspect ratio micro-mechanical structures in Poly(Methyl MethAcrylate). In particular we focus on the fabrication of individual plastic refractive microlenses featuring a wide range of numerical apertures, diameters and pitches and their 2D arrays. We give a detailed description of the microlens fabrication technique and the calibration procedure that goes along with it. We highlight the quantitative geometrical and optical characteristics of these DLP microlenses and we demonstrate the reproducibility of their fabrication process. We also illustrate the prototyping flexibility of DLP by making arrays featuring microlenses with different sags, pitches and diameters ...
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36th week of 2010 patent applcation highlights part 7
LIGHT EMITTING DEVICE WITH MICROLENS ARRAY - A method of manufacturing a micro-lens array and light-emitting device, comprising forming a first structured polymer film with close packed surface cavities having a mean diameter of less than 20 micrometers and a relatively lower surface energy surface, forming a transparent second structured film with an array of microlenses formed thereon corresponding to the cavities of the first structured film, wherein the second structured film comprises a relatively high surface energy material and has a refractive index greater than 1.45, and wherein the microlenses are randomly distributed, separating the second structured film with the micro-lens array from the first structured polymer film, and attaching the second structured film to a transparent substrate or cover of a light-emitting device through which light is emitted. Use of microlens arrays formed from relatively high surface energy materials enables matching refractive index of microlens array to ...
Extended depth-of-field microscopy with a high-speed deformable mirror | (2017) | Shain | Publications | Spie
Wide-field fluorescence microscopy is generally limited to either small volumes or low temporal resolution. We present a microscope add-on that provides fast, light-efficient extended depth-of-field (EDOF) using a deformable mirror of update rate 20kHz. Out-of-focus contributions in the raw EDOF images are suppressed with a deconvolution algorithm derived directly from the microscope 3D optical transfer function. Demonstrations of the benefits of EDOF microscopy are shown with GCaMP-labeled mouse brain tissue ...
Deformable Mirrors | Edmund Optics Inc. | New Products | Jul 2010 | Photonics Spectra
!%Edmund Optics%! has released high-performance deformable mirrors that correct optical aberrations through wavefront manipulation and control, intro
Micromachines | Free Full-Text | Liquid Gradient Refractive Index Microlens for Dynamically Adjusting the Beam Focusing | HTML
An in-plane liquid gradient index (L-GRIN) microlens is designed for dynamically adjusting the beam focusing. The ethylene glycol solution (core liquid) withde-ionized (DI) water (cladding liquid) is co-injected into the lens chamber to form a gradient refractive index profile. The influences of the diffusion coefficient, mass fraction of ethylene glycol and flow rate of liquids on the refractive index profile of L-GRIN microlens are analyzed, and the finite element method and ray tracing method are used to simulate the convection-diffusion process and beam focusing process, which is helpful for the prediction of focusing effects and manipulation of the device. It is found that not only the focal length but the focal spot of the output beam can be adjusted by the diffusion coefficient, mass fraction and flow rate of liquids. The focal length of the microlens varies from 942 to 11 μm when the mass fraction of the ethylene glycol solution varies from 0.05 to 0.4, and the focal length changes from 127.1
Digital micromirror device - Wikipedia
The mirrors themselves are made out of aluminum and are around 16 micrometers across. Each one is mounted on a yoke which in turn is connected to two support posts by compliant torsion hinges. In this type of hinge, the axle is fixed at both ends and twists in the middle. Because of the small scale, hinge fatigue is not a problem  and tests have shown that even 1 trillion (1012) operations do not cause noticeable damage. Tests have also shown that the hinges cannot be damaged by normal shock and vibration, since it is absorbed by the DMD superstructure. Two pairs of electrodes control the position of the mirror by electrostatic attraction. Each pair has one electrode on each side of the hinge, with one of the pairs positioned to act on the yoke and the other acting directly on the mirror. The majority of the time, equal bias charges are applied to both sides simultaneously. Instead of flipping to a central position as one might expect, this actually holds the mirror in its current position. ...
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Benefit of Adaptive Optics Aberration Correction at Preferred Retinal Locus
This thesis is about our peripheral vision. Peripheral vision is poor compared to central vision, due to both neural and optical factors. The optical factors include astigmatism, defocus and higher order aberrations consisting mainly of coma. Neurally, the density of ganglion cells decreases towards the periphery, which limits the sampling density. The questions that this thesis attempts to answer are how much and under which circumstances correction of optical errors can improve peripheral vision. For this, an adaptive optics system has been constructed with a wavefront sensor and a deformable mirror working in closed loop to perform real-time correction of optical errors. To investigate vision, psychophysical routines utilizing Bayesian methods have been evaluated and modified for peripheral vision to handle the presence of aliasing, fixation instability and rapid fatigue.. We found that correcting both refractive errors and higher order aberrations improved peripheral low-contrast resolution ...
Numerical simulation in adaptive optics<...
TY - GEN. T1 - Numerical simulation in adaptive optics. AU - Kanev, Feodor Yu. AU - Lukin, Vladimir V.. AU - Makenova, Nailya Altykhanovna. PY - 2005. Y1 - 2005. N2 - A numerical model of a typical adaptive optics system is described in the report. The developed computer application corresponding to the model includes all the main elements of a real system, namely, computer codes simulating radiation propagation in a turbulent atmosphere with thermal blooming and codes simulating the elements of adaptive optics system (a model of a Shack-Hartmann wavefront sensor, two algorithms of dislocation localization, and a model of adaptive mirror with continuous surface). In the report we include solutions to the some of adaptive optics problems obtained with the model: realization of amplitude-phase control in two-mirror adaptive system, the method to improve the stability of correction for thermal blooming, evaluation of a Shack-Hartmann sensor performance, and some others. These results demonstrate ...
Patent US5247180 - Stereolithographic apparatus and method of use - Google Patents
A stereolithographic apparatus is disclosed comprising a vat, a working surface in the vat, an elevating mechanism for controlling the level of liquid within the vat relative to the working surface, an illumination source for emitting radiation, and an area array deformable mirror device. The illumination source emits radiation which is operable to harden a stereolithographic liquid, while the deformable mirror device is operable to reflect the incident radiation onto the surface of the liquid. The deformable mirror device can harden an entire lamina of liquid in one brief exposure interval increasing throughout without sacrificing resolution.
Direct writing of cylindrical microlenses on polymer substrates - IEEE Conference Publication
The fabrication of cylindrical microlenses and microlens arrays by CO/sub 2/ laser irradiation of polyvinylidene fluoride substrates (PVDF) has been demons
Optimization of compression molding of stand-alone microlenses: Simulation and experimental results - Mirkhalaf - 2010 -...
Hot compression molding is a promising method to fabricate polymer stand-alone microlenses. A reliable theoretical as well as statistical analysis is required for the optimization of the process to minimize the residual stresses and to predict the amount of springback to achieve a better replication of the mold profile. This article in this context focuses on the finite element simulation (FES), optimization as well as experimental validation of hot compression molding of polymer stand-alone microlenses. Three steps such as molding, cooling, and demolding, under different molding parameters, were analyzed using ABAQUS/standard solver and the results were compared with experimental results. Compression test and compression relaxation test have been conducted at different temperatures and strain rates to characterize the rheological behavior of material. Two material models, linear viscoelastic and hyperelastic-viscoelastic models, were developed and used for compression test simulations. ...
Patent US5208702 - Objective lens system for endoscopes - Google Patents
An objective lens system for endoscopes comprising, in the order from the object side, a first lens component having a negative refractive power, a second lens component having a positive refractive power, an aperture stop arranged right after the second lens component, and a rear lens unit comprising a third lens component designed as a cemented doublet consisting of a lens element having a positive refractive power and a lens element having a negative refractive power. Said objective lens system for endoscopes has a wide field angle, a compact design, a small number of lens elements and favorably corrected aberrations.
Olympus Mplanfl 100x 0.90 Bd Microscope Objective Lens, Mplanfl | Mcalesters Blog
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Wide Field and Planetary Camera 2 - Wikipedia
The Wide Field and Planetary Camera 2 (WFPC2) is a camera formerly installed on the Hubble Space Telescope. The camera was built by the Jet Propulsion Laboratory and is roughly the size of a baby grand piano. It was installed by servicing mission 1 (STS-61) in 1993, replacing the telescopes original Wide Field and Planetary Camera (WF/PC). WFPC2 was used to image the Hubble Deep Field in 1995, the Hourglass Nebula and Egg Nebula in 1996, and the Hubble Deep Field South in 1998. During STS-125, WFPC2 was removed and replaced with the Wide Field Camera 3 as part of the missions first spacewalk on May 14, 2009. After returning to Earth, the camera was displayed briefly at the National Air and Space Museum and the Jet Propulsion Laboratory before returning to its final home at the Smithsonians National Air and Space Museum. WFPC2 was built by NASAs Jet Propulsion Laboratory, which also built the predecessor WF/PC camera launched with Hubble in 1990. WFPC2 contains internal corrective optics to ...
US7113342B2 - Composite structure for light diffusion - Google Patents
The present invention disclose a composite structure for light diffusion, including at least one carrier media layer and a microlens system comprising a plurality of microlenses thereon. A transparent material for enlarging the shape is coated on each microlens to cover the gaps between the microlens. Partial surface of the transparent material can be coated a light absorbing layer for glare reduction. Besides, the microlens can be or asymmetric or arranged in random, non-periodic array for interference reduction.
Patente US20040218293 - Packaged micromirror array for a projection display - Google Patentes
In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the collection optics, in the present invention, micromirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, is not however, orthogonal to any substantial portion of sides of the individual micromirrors in the array. Orthogonal sides cause incident light to diffract along the direction of micromirror switching, and result in light leakage into the on state even if the micromirror is in the off state. This light diffraction decreases the contrast ratio of the micromirror. The micromirrors of
Localized plasmonic structured illumination microscopy with an optically trapped microlens - Nanoscale (RSC Publishing)
Localized plasmonic structured illumination microscopy (LPSIM) is a recently developed super resolution technique that demonstrates immense potential via arrays of localized plasmonic antennas. Microlens microscopy represents another distinct approach for improving resolution by introducing a spherical lens
The Gemini Observatory - Preprint #69
We describe the purpose and sample results of a wave optics propagation simulation developed to study multi-conjugate adaptive optics for 4-10 m class telescopes. This code was developed to assess the impact of diffraction effects and a variety of implementation error sources upon the performance of the Gemini-South MCAO system. These effects include: Hartmann sensing with extended and elongated laser guide stars, optical propagation effects through the optics and atmosphere, laser guide star projection through the atmosphere, deformable mirror and wave front sensor misregistration, and calibration for non-common path errors. The code may be run in either a wave optics or geometric propagation mode to allow the code to be anchored against linear analytical models and to explicitly evaluate the impact of diffraction effects. The code is written in MATLAB, and complete simulations of the Gemini-South MCAO design (including 3 deformable mirrors with 769 actuators, 5 LGS WFS with 1020 subapertures, ...
Deformable mirror corrects errors
Scientists are working on ways of making the mirrors more temperature-resistant and getting rid of the deformation. However, this difficult undertaking only works up to a point. Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena are pursuing a completely different approach. Weve developed a mirror that doesnt prevent deformation by the laser, but corrects it, explains Dr. Claudia Reinlein, from Fraunhofer IOF. By deliberately heating up the mirror to a precisely controlled level, we balance out the unwanted deformation by the laser.. Working with colleagues from Fraunhofer IKTS and Ilmenau University of Technology, the scientist designed a ceramic mirror with a copper layer on the front and built-in temperature sensors and filaments. When a laser beam heats up the mirror, the sensors detect the change. Software calculates how strongly the mirror is deforming from the heat and sends a corresponding current of electrical power through the ...
Eye Doctors for Vision Improvement and Myopia Reduction
The minus lens is merely an aid to vision, i.e., compensation by external means. In the majority of cases, naked-eye vision gets worse with the traditional minus lens correction. . . . At times, the best that I can do is to emphasize that the use of (minus lens) glasses be restricted to chalk board, and always must be removed after class. . . . The earlier age you begin wearing the minus lens, the faster vision deteriorates. The minus lens can make vision worse all by itself! Many scientists, engineers and health workers have formed this opinion - that the minus lens is definitely harmful to young kids long-term vision. . . . . My goal is to look to the future and begin preventive methods which can be effective for the child who is on the threshold of myopia. Today, I make it clear that my mission and task is to try my best to discuss the alternate opinion on the therapeutic use of the plus lens - instead of the compensatory use of minus lens. . . . I have supported several hundred children ...
US20080125510A1 - Surface buckling method and articles formed thereby - Google Patents
A method for generating spontaneously aligned surface wrinkles utilizes control of local moduli-mismatch and osmotic pressure. The method includes modifying the surface of an elastomeric layer to form a superlayer that is stiffer and/or less absorbent than the elastomeric layer. The elastomeric layer is then swollen with a polymerizable monomer, which causes buckling of the superlayer. The monomer is then polymerized, dimensionally stabilizing the surface buckling. The budded surfaces generated by the method are useful in a wide variety of end-use applications, including microlenses, microlens arrays, compound microlenses, diffraction gratings, photonic crystals, smart adhesives, mechanical strain sensors, microfluidic devices, and cell culture surfaces.
Two Color Dynamic Scene Generator | SBIR.gov
OPTRA proposes the development of a two-color IR source simulator based on fused projected images of two digital micromirror devices (DMDs), one for each spectral band. The system employs a broadband IR (thermal) source whose energy is spectrally filtered via a dichroic beamsplitter and bandpass filters prior to being imaged onto each DMD. The on reflected image from each DMD is then recombined by the dichroic beamsplitter, and the fused beam is expanded by a telescope and transmitted towards the unit under test. The relative intensities of the two bands are controlled through the duty cycle of on versus off images reflected by each DMD. Because the IR source temperature is constant, response is considerably faster than resistive based simulators; similarly, thermal management issues are significantly less complex than with resistive arrays whose time constant depends on thermal management. Simplified thermal management may result in a lower power, more fieldable system. This approach ...
Shedding Light on Neural Systems - The Harvard Undergraduate Research Journal
Obviously, the field has come a long way since Cricks initial speculation. In fact, last year, another major development occurred right here on the Harvard campus. In January 2011, the Samuel Lab of the Center for Brain Science published their work on CoLBeRT, an optogenetic system that allows them to Control Locomotion and Behavior in Real Time (4). CoLBeRT uniquely allows neural manipulation in freely moving, unanesthetized organisms like C. elegans. Though the 302 neurons of C. elegans have been extensively mapped, the Samuel Lab wanted to examine patterns of neural activity underlying common behaviors exhibited by these worms.. To target individual motor neurons, they used a digital micromirror device (DMD). Laser lights of the appropriate frequency are reflected off a series of mirrors onto the DMD, which focuses the light with high spatial specificity on the worm (genetically engineered to express ChR2 and NpHR). The lasers specificity is so precise that the system can illuminate the ...
Publikationen | Max-Planck-Institut für biophysikalische Chemie
De Beule, P.; de Vries, A. H. B.; Arndt-Jovin, D. J.; Jovin, T. M.: Generation-3 programmable array microscope (PAM) with digital micro-mirror device (DMD). In: SPIE proceedings, Bd. 7932, 7932OG (Hg. Douglass, M. R.; Oden, P. I.). Conference on Emerging Digital Micromirror Device Based Systems and Applications III, San Francisco, Calif., 26. Januar 2011. SPIE, Bellingham, Wash. (2011 ...
DPs Expansion is Underway!
2011 marks DPIs 15th anniversary, and what a monumental milestone it is. With so many years of pragmatic growth and a sound corporate structure, the time is right for DPI to extend our product offerings and bring our precision displays to select new markets.. -- Digital Projection International (DPI) was founded with one key objective; to innovate the projection technology of the future in order to advance the capabilities of large-screen displays. Since our company first took on this challenge, we have worked closely with our customers to assure our products create the most precise imagery possible within every application. From our strategic partnership with Texas Instruments which led to refinement of the Digital Micromirror Device™ for projection applications and the worlds first 3-chip DLP projector, to receiving the only Emmy Awards ever awarded to a projector manufacturer, weve seen many successes. DPIs progress over the years is proof that equal parts hard work and product ...
DLP660TE DLP® 0.66 4K UHD DMD | TI.com
The TI DLP660TE digital micromirror device (DMD) is a digitally controlled micro-opto-electromechanical system (MOEMS) spatial light modulator (SLM) that enables bright, affordable full 4K UHD display solutions.
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MacroView is a research Macro Zoom Fluorescence Microscope. The MVX10 addresses the tradeoffs between stereo and compound imaging systems, offering high numerical apertures from a compound microscope along with long working distances and larger fields of view from a stereomicroscope.. ...
OSA | Laser tomography adaptive optics: a performance study
We present an analytical derivation of the on-axis performance of adaptive optics systems using a given number of guide stars of arbitrary altitude, distributed at arbitrary angular positions in the sky. The expressions of the residual error are given for cases of both continuous and discrete turbulent atmospheric profiles. Assuming Shack-Hartmann wavefront sensing with circular apertures, we demonstrate that the error is formally described by integrals of products of three Bessel functions. We compare the performance of adaptive optics correction when using natural, sodium, or Rayleigh laser guide stars. For small diameter class telescopes ( ...
Prof. Chang Kwon Hwangbo Profile
The Shack-Hartmann or Hartmann-Shack wavefront sensors are particular forms of the Hartmann sensor and are the most commonly used in adaptive optics. The traditional Hartmann screen in the pupil is replaced by an array of small lenslets at a conjugate to an image of the pupil or deformable mirror. Each lenslet forms an independent image of the incoming wavefront. Shifts in the positions of these images can be shown by simple geometric optics to be proportional to the mean wavefront gradient over each lenslet. The measurement range or dynamic range of a conventional Shack-Hartmann sensor is normally limited by the sub-aperture size of the detector plane, in which each spot should remain. In order to overcome this restriction, several methods, such as modified unwrapped algorithm or a spatial-light modulator as a shutter, have been proposed. We first simulated the image forming of a conventional Shack-Hartmann wavefront sensor for highly aberrated spherical aberrations through computer simulation, ...
Sep 06, 2011 Able to meet need for working distances from 0.3-30 mm, apochromatic objectives are customized with high numerical apertures and long working distances for use with various sample sizes and applications. Lenses are also tailored to function at wavelengths from visible light at 390-750 nm to near infrared (NIR) at 700-1,400 nm. Depending on type of studies being done, 2-photon microscopy systems... Read More. ...
Sliding Mode Control of a 2D Torsional MEMS Micromirror with Sidewall Electrodes: Science & Engineering Journal Article | IGI...
Sliding Mode Control of a 2D Torsional MEMS Micromirror with Sidewall Electrodes: 10.4018/ijimr.2013010102: This paper presents a sliding mode control scheme to improve the positioning performance of a 2-Degree-of-freedom (DOF) torsional MEMS micromirror with
Rotation stage pure rotation HASO R-flex Mirao axis tip-tilt
Rotation stage for the alignment of HASO wavefront sensors R-Flex and Mirao deformable mirror rotation axis close to the microlenses for pure rotation
What is an ocular lens on a microscope | www.QACollections.com
The ocular lens is one of two lenses in the optical train of a microscope, the other being the objective lens. Located in the eyepiece, the ocular lens is the nearest lens to the observer's eye providing additional magnification and directing the image into the observer's eye.Total MagnificationThe total magnification of a microscope is the product of the magnification of the ocular lens and the objective lens. For example, a 10x ocular lens and a 40x objective lens produce a total magnification of 400x.Monocular vs. Binocular MicroscopesMonocular microscopes have one ocular lens, while binocular microscopes have two ocular lenses--one for...
Optical diffraction tomography using a digital micromirror device for stable measurement of 4-D refractive index tomography of...
Optical diffraction tomography using a digital micromirror device for stable measurement of 4-D refractive index tomography of ...
Ultrahigh-speed ultrahigh-resolution adaptive optics: Optical coherence tomography system for in-vivo small animal retinal...
TY - GEN. T1 - Ultrahigh-speed ultrahigh-resolution adaptive optics. T2 - Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XVII. AU - Jian, Yifan. AU - Xu, Jing. AU - Zawadzki, Robert. AU - Sarunic, Marinko V.. PY - 2013/5/22. Y1 - 2013/5/22. N2 - Small animal models of human retinal diseases are a critical component of vision research. In this report, we present an ultrahigh-resolution ultrahigh-speed adaptive optics optical coherence tomography (AO-OCT) system for small animal retinal imaging (mouse, fish, etc.). We adapted our imaging system to different types of small animals in accordance with the optical properties of their eyes. Results of AO-OCT images of small animal retinas acquired with AO correction are presented. Cellular structures including nerve fiber bundles, capillary networks and detailed double-cone photoreceptors are visualized.. AB - Small animal models of human retinal diseases are a critical component of vision research. In this report, we ...
Sensors | Free Full-Text | Manufacture of Micromirror Arrays Using a CMOS-MEMS Technique
In this study we used the commercial 0.35 µm CMOS (complementary metal oxide semiconductor) process and simple maskless post-processing to fabricate an array of micromirrors exhibiting high natural frequency. The micromirrors were manufactured from aluminum; the sacrificial layer was silicon dioxide. Because we fabricated the micromirror arrays using the standard CMOS process, they have the potential to be integrated with circuitry on a chip. For post-processing we used an etchant to remove the sacrificial layer and thereby suspend the micromirrors. The micromirror array contained a circular membrane and four fixed beams set symmetrically around and below the circular mirror; these four fan-shaped electrodes controlled the tilting of the micromirror. A MEMS (microelectromechanical system) motion analysis system and a confocal 3D-surface topography were used to characterize the properties and configuration of the micromirror array. Each micromirror could be rotated in four independent directions.
Presbia Submits Investigational Device Exemption for the Presbia Flexivue Microlens
IRVINE, Calif.--(BUSINESS WIRE)--Nov 9, 2012--Presbia, a medical device company and leader in near vision restoration, announced today that it has received a letter from the U.S. Food & Drug Administration (FDA) indicating that it is being actively considered for an Investigational Device Exemption (IDE, G120225) for its revolutionary Presbia Flexivue Microlens, an implantable corneal inlay solution for presbyopia, the age-related loss of near vision.. Presbia also announced that Dr. Robert Maloney, Clinical Professor of Ophthalmology at University of California, Los Angeles and Director of the Maloney Vision Institute in Los Angeles, California, will serve as Medical Monitor for the duration of the Presbia Flexivue Microlens U.S. IDE study, which is a required part of the medical device approval process.. Submission of this IDE is a significant milestone for the Presbia Flexivue Microlens, said Zohar Loshitzer, Chief Executive Officer of Presbia. In addition, we are excited that Dr. Maloney ...
Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and...
There is a large number of methods that can be used for quantifying the viability of cells. One of the established methods of determining cell viability is exclusion staining. In this method, dead cells are stained, and after counting the number of stained and unstained cells, a number between 0% and 100% is used to indicate the cell viability of the sample.34-36 There are multiple exclusion stains used in industry to perform yeast viability testing.37-39 One commonly used stain is methylene blue,40,41 which is inexpensive, can be stored at room temperature, and has a relatively low toxicity to humans.42 However, conventional methylene blue exclusion testing methods suffer from (1) false positive results at longer exposure times,39 and (2) operator subjectivity, which is an important disadvantage compared to fluorescence-based staining methods (e.g., using propidium iodide).43,44 Our computational platform does not suffer from these reported disadvantages of methylene blue because (1) it ...
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Despite recent advances, the tissue clearing technologies have a fundamental limitation: the working distance of optical microscopy. Without physical sectioning, an objective lens with high numerical aperture (≥1.2) for resolving submicron-resolution details does not have enough working distance (≥0.28 mm) to visualize cellular structures that are more than several millimeters deep. This limitation can be partially addressed by shrinkage-mediated imaging, which reduces the tissue volume after clearing (Pan et al., 2016). However, serial sectioning is still required for 3D imaging and reconstruction of large tissues.. Serial sectioning has been used with transmission EM to reconstruct the whole-body connectome of Caenorhabditis elegans (White et al., 1986; Xu et al., 2013) and larval Drosophila (Ohyama et al., 2015) as well as the partial optic medulla connectome in Drosophila (Takemura et al., 2013). However, the use of transmission EM in connectome reconstruction is limited by the ...
Effect of Adaptive-Optics-Corrected Ocular Aberrations on Visual Acuity as a Function of Luminance and Polarity | IOVS | ARVO...
Purpose: : To investigate the effect of correcting ocular aberrations on visual acuity (VA), both for white-on-black (WoB) and black-on-white (BoW) letters at various luminances. To assess the relative contribution of optical and neural factors to the visual acuity measured in those conditions. Methods: : We measured VA with natural aberrations and under static aberration correction with adaptive optics (AO). The custom-made instrument included a Hartmann-Shack wavefront sensor, a magnetic deformable mirror with 52 actuators (MIRAO, Imagine Eyes), a motorized Badal system, a pupil monitoring CCD, and a high brightness minidisplay. VA was measured using a four alternative choice procedure with tumbling Snellen E letters (Quest algorithm with 50 trials presented during 0.5 s, programmed in Psychotoolbox). VA was measured as a function of luminance (0.8, 1.6, 2.5, 5, 16, 25 and 50 cd/m2), starting with the dimmest test, and allowing for adaptation. Three conditions were measured: WoB letters under ...
Viral plaque analysis on a wide field-of-view, time-lapse, on-chip imaging platform - CaltechAUTHORS
The observation of viral plaques is the standard method for determining the viral titer and understanding the behaviors of viruses. Here, we report the application of a wide field-of-view (FOV), time-lapse, on-chip imaging platform, termed the ePetri, for plaque analysis of murine norovirus 1 (MNV-1). The ePetri offers the ability to dynamically track plaques at the individual cell death event level over a wide FOV of 6 mm × 4 mm. As demonstration, we captured high-resolution time-lapse images of MNV-1-infected cells at 30 min intervals. We implemented a customized image-processing program containing a density-based clustering algorithm to analyze the spatial-temporal distribution of cell death events to identify plaques at their earliest stages. By using the results in a viral titer count format, we showed that our approach gives results that are comparable to conventional plaque assays. We further showed that the extra information collected by the ePetri can be used to monitor the dynamics of ...
2003.05293] Real time computer generation of three-dimensional point cloud holograms through GPU implementation of compressed...
Abstract: Phase-only spatial light modulators can be employed to structure laser light in complex three dimensional focusing patterns, with a variety of applications. While spatial light modulators have typical refresh frequencies of tens of Hz, the computation time of three dimensional holograms ranges between a few seconds and a few minutes, therefore limiting the use of the maximum refresh rate of spatial light modulators to either pre-calculated sequences of high quality holograms, or low quality holograms only for real time update. Here, we propose the implementation of a recently developed compressed sensing Gerchberg-Saxton algorithm on a consumer graphical processor allowing the generation of high quality holograms at video rate ...
Numerical Aperture Of Optical Fiber Pdf
Measurement of the numerical aperture of optical fibers CORE - thod to determine the local numerical aperture and the light output power attenuation with the bending of an optical waveguide. We showed that this method can be applied only when the optical waveguide is curved dur- ing the manufacturing at a temperature close to glass melting. In this case, the core and the cladding refractive index are modified by temperature effects independently of the
Microscope World Blog: Biological vs. Metallurgical Microscope Objectives
The objectives for these two categories are distinct and are marked on the barrel of the objective. The objective shown below is for reflected light. The BD indicates that this microscope objectives is intended for brightfield / darkfield illumination, a standard technique in reflected light microscopy. (BD reflected light objectives also usually have a larger thread mount and barrel to accommodate the additional light path. These lenses will not fit the standard nosepiece). EPI indicates that this microscope objective is used for epi-illumination. Immediately after the infinity symbol there is /0 - this means the objective is intended to be used without a cover slip. This is also the main difference in the design of reflected light microscope objectives ...
OBJECTIVE LENSES | Janos Technology LLC | New Products | Nov 2005 | Photonics Spectra
The Asio microscopic objective lenses produced by !%Janos Technology Inc.%! support imagers with a standardized back-working distance, stop location a
This bi-weekly seminar aims at bringing together several communities of adaptive optics users and developers across UC campuses to foster rich exchanges of expertise and experience, continuing the tradition that has grown during the existence of the NSF-funded Center for Adaptive Optics. Talks are intended for mixed audiences from the astronomy, vision science and instrument development communities, providing an up-to-date view of what current adaptive optics systems do and how they will improve in upcoming years ...
High-speed scattering medium characterization with application to focusing light through turbid media
We introduce a phase-control holographic technique to characterize scattering media with the purpose of focusing light through it. The system generates computer-generated holograms implemented via a deformable mirror device (DMD) based on micro-electro-mechanical technology. The DMD can be updated a …
4 MP Deep Cooled CCD Camera with Wide Field of View SPOT Xplorer Slider
Deep cooled CCD cameras in monochrome & slider configurations for wide field fluorescence microscopy, gel documentation, bioluminescence, & more.
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Infrared (IR) therapy stimulates the bodys natural healing mechanisms - Doctors eBook
New findings : NASA was one in all the primary to acknowledge Red light-weight as being essential to human survival. Red light-weight triggers a chemical change that causes the cells in our body to regenerate. voyage includes red light-weight. In 1998 a noble prize was awarded for providing proof that red light-weight was essential for human survival. the explanation we have an inclination to use junction rectifier lightweight is as a result of junction rectifier lightweight is delivered in AN passing single wave length thats crucial to obtaining the right cell chemical change. Current clinical study completed solar calendar month twelve, 2019 by state capital University school exposing that the standard go to declare knee or back pain could also be a DANGEROUS steroid shot that the shots cause plenty of injury and dont facilitate to heal or repair the injury and provide of the pain. The shots exclusively block the bodies warning system PAIN thus any injury will occur. victimization Red ...
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ESCRS Official Website | European Society of Cataract & Refractive Surgeons
LCA was obtained from psychophysical and wavefront sensing measurements of best-focus at 8 different wavelengths on 18 eyes (9 subjects) bilaterally implanted with hydrophobic Podeye IOLs and hydrophobic Poday IOLs (by PhysIOL) in each eye. Measurements were performed using psychophysical (480-700 nm) and wavefront sensing (480-950 nm) methods in a custom-developed Adaptive Optics system. Chromatic difference of focus curves were obtained by measuring best-focus at each wavelength. Psychophysical best-focus was manually searched by the subject while viewing a target. Objective best focus was obtained from the defocus Zernike terms. LCA was obtained from the polynomial fitting of those curves ...
Telescopic sight mounted on a rifle.. Telescopic Sight - An optical sight, offering some magnification, often variable, with some kind of adjustable aiming grid inside (a reticle), which when mounted on a firearm, usually a rifle, makes sighting easier. Using iron sights, as one ages, presbyopia (the deterioration of nearfield focusing ability) makes it difficult to focus simultaneously on the three planes of rear sight, front sight, and target. It is easier to aim a rifle with a telescopic sight because one may simply place the reticle on the target.. Telescopic sights are designated first by their power, and then by the diameter of their objective lens. 4x20 would mean 4 times magnification and with a 20mm objective lens. 3-12x50 would mean a variable scope, adjustable between 3 and 12 times magnification and with a 50mm objective lens for better light gathering. The Hallowell & Co. Illustrated Firearms Dictionary is for informational purposes only. We do not necessarily offer the items ...
LOF - UMR 5258 - Periodic defect patterns and guided nanoparticle assembly in smectic liquid crystal films
Periodic micropatterns due to the nucleation and self-assembly of defect domains can be obtained in smectic liquid crystal films confined under conflicting boundary conditions. The domain dimensionality (1D/2D), symmetry and size, ranging from less than 0.5 µm to several µm, can be controlled by varying the film thickness and boundary conditions (anchoring), and applying an external electric field. Smectic micropatterns are useful for various applications, such as templates for soft lithography and microlens arrays, where pattern regularity over large areas, rapid self-assembly and a soft responsive character are demanded.. We focus on the ability of such micropatterns to organize the spatial distribution of nanoparticle dispersions owing to a strong interaction between nanoparticles and the core of liquid crystal defects. Namely, 1D patterns induce the formation of nanochains trapped within linear defects with a cross-sectional size comparable to the nanoparticle diameter. Moreover, chains ...
Unilateral spatial neglect occurs frequently following a brain lesion in especially the right hemisphere (25-30% of all stroke patients, Appleros et al, 2002), resulting in a failure to report or respond to stimulation in contralesional hemispace. Prism adaptation is the most widely studied method to alleviate the symptoms of neglect. Effects of a single session of prism adaptation have been reported across clinical measures, but also in more daily situations, such as wheelchair navigation (Rossetti et al, 1999) and postural control (Tilikete et al, 2001). The current study will focus on the effects of an intensive programme of exposure to prism adaptation (i.e. daily exposure during two weeks) and whether more permanent changes in spatial awareness can be objectified. To assess the effects of prism adaptation in the proposed study, patients will receive either prism adaptation or sham adaptation. We expect longer-lasting, more general beneficial effects after prism adaptation compared to sham ...
Biblio | Middlebury
Durst, Michael E, and Chris Xu. Kilohertz Tunable Dispersion Compensation With A Bimorph Piezo Deformable Mirror. Conference On Lasers And Electro-Opticsconference On Lasers And Electro-Optics/international Quantum Electronics Conference. Baltimore, MarylandWashington, D.C.: OSA, 2009. CMLL6. Web. Conference On Lasers And Electro-Opticsconference On Lasers And Electro-Optics/international Quantum Electronics Conference ...
Synthesis and characterization of Mn0.5Zn0.5Fe2O4 and Fe3O4 nanoparticle ferrofluids for thermo-electric conversion - Surrey...
Science & Technology, Technology, Physical Sciences, Materials Science, Multidisciplinary, Physics, Condensed Matter, Materials Science, Physics, MATERIALS SCIENCE, MULTIDISCIPLINARY, PHYSICS, CONDENSED MATTER, Ferrofluid, Heat transfer, Energy harvesting, VARYING MAGNETIC-FIELDS, HEAT-TRANSFER, THERMOMAGNETIC CONVECTION, NATURAL-CONVECTION, DEFORMABLE MIRROR, FLUID, FLOW ...
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SCUBAPRO SYNERGY MINI MASK. - Aquanauts
The new SYNERGY MINI is the smaller version of the best selling Synergy Twin Mask.. With a downsized frame and skirt to fit smaller faces, yet still containing the TruFit Technology.. The dual lens design has been made to be low volume yet still offer a wide field of view.. Now comes as standard with a colour-coordinated Comfort Strap. The mask is available in a selection of different colours allowing you to express your personality.. The new SYNERGY MINI is the smaller version of the best selling Synergy Twin Mask.. With a downsized frame and skirt to fit smaller faces, yet still containing the TruFit Technology.. The dual lens design has been made to be low volume yet still offer a wide field of view.. Now comes as standard with a colour-coordinated Comfort Strap. The mask is available in a selection of different colours allowing you to express your personality. ...
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Uncoated glasses lens (top) versus lens with antireflective coating. Note the tinted reflection from the coated lens. ... Corrective lenses. Opticians may recommend "anti-reflection lenses" because the decreased reflection enhances the ... Antireflective ophthalmic lenses should not be confused with polarized lenses, which decrease (by absorption) the visible glare ... Examples include anti-glare coatings on corrective lenses and camera lens elements, and antireflective coatings on solar cells. ...
A gradient-index lens with a parabolic variation of refractive index (n) with radial distance (x). The lens focuses light in ... It determines the focusing power of lenses, the dispersive power of prisms, the reflectivity of lens coatings, and the light- ... 276 The crystalline lens of the human eye is an example of a GRIN lens with a refractive index varying from about 1.406 in the ... The focal length of a lens is determined by its refractive index n and the radii of curvature R1 and R2 of its surfaces. The ...
Digital single-lens reflex camera
There are also lens adapters that allow a lens for one lens mounts to be used on a camera body with a different lens mount but ... Interchangeable lenses. Main articles: Photographic lens and Lenses for SLR and DSLR cameras ... Fixed or interchangeable lenses. Unlike DSLRs, most digital cameras lack the option to change the lens. Instead, most ... Like SLRs, DSLRs typically use interchangeable lenses (1) with a proprietary lens mount. A movable mechanical mirror system (2) ...
Full face diving mask
Shape of faceplate or lenses. Several shapes have been used for faceplates and lenses: ... A full-face mask consists of a transparent faceplate (lenses, or window) through which the diver can see, a connection to a ... There is usually a strong plastic frame which supports the faceplate (or lenses) and a demand valve, but in some cases the ... In some old masks, largely for industrial use out of water, small separate lenses above a rounded opaque nose-and-mouth mask, ...
Olympus OM system
Zuiko lenses specifications Lens Angle of view Elements - Groups Diaphragm Aperture range Closest focus Smallest field ... Prototype lenses. Manual Zuiko lenses that were never marketed: *18 mm/f3.5, prototype of 18 mm/f3.5, L.zuiko with 12 ... The Olympus OM System (O = Olympus, M = Maitani) was a line of 35mm single-lens reflex cameras, lenses and accessories sold by ... The OM Series lenses had the aperture control ring located at the front of the lens barrel. This was done to move it away from ...
Lenses. Optometrists can supply colored spectacle lenses or a single red-tint contact lens to wear on the non-dominant ... A 1981 review of various studies to evaluate the effect of the X-chrom contact lens concluded that, while the lens may allow ... Siegel, I. M. (1981). "The X-Chrom lens. On seeing red". Surv Ophthalmol. 25 (5): 312-24. doi:10.1016/S0039-6257(81)80001-X. ... Lenses that filter certain wavelengths of light can allow people with a cone anomaly, but not dichromacy, to see better ...
Introduction to general relativity
Observational astronomy uses lensing effects as an important tool to infer properties of the lensing object. Even in cases ... In particular, gravitational lensing provides one way to measure the distribution of dark matter, which does not give off light ... Introductions to gravitational lensing and its applications can be found on the webpages Newbury 1997 and Lochner 2007. ... Newbury, Pete (1997), Gravitational lensing webpages, archived from the original on 2012-12-06, retrieved 2007-06-12. ...
Eve Kosofsky Sedgwick
The queer lens. Sedgwick aimed to make readers more alert to the "potential queer nuances" of literature, encouraging the ...
Tests of general relativity
Gravitational lensing. One of the most important tests is gravitational lensing. It has been observed in distant ... Gravitational lensing. Astronomers using the Hubble Space Telescope and the Very Large Telescope have made precise tests ... In January 2012, LARES satellite was launched on a Vega rocket to measure Lense-Thirring effect with an accuracy of about 1 ... The nearby galaxy ESO 325-G004 acts as a strong gravitational lens, distorting light from a distant galaxy behind it to create ...
Contact lenses. Different types of contact lenses may be used to delay or eliminate the need for corneal transplantation ... In corneal disorders where vision correction is not possible by using contact lenses, intrastromal corneal ring segments may be ... with an artificial lens installed in the transplanted piece. ... adequately correct their vision with glasses or contact lenses ...
"Plastic" (polycarbonate) lenses can become cloudy and discoloured. This is due to oxidation of the painted-on lens hardcoat by ... This may be achieved by methods including adhering opaque decals or prismatic lenses to a designated part of the lens. Some ... lens, or reflector, or a yellow filter between the bulb and the lens. Filtration losses reduced the emitted light intensity ... Lens optics. A light source (filament or arc) is placed at or near the focus of a reflector, which may be parabolic or of ...
Lens types. Orthokeratology lenses are made by a number of companies and all use special gas-permeable contact lenses to ... "Orthokeratology , Ortho-K lenses , Myopic degeneration prevention". 2018-07-04.. *^ Orthokeratology contact lenses cause ... Rigid lenses are generally considered to be not as comfortable as soft lenses, but Ortho-K is claimed to avoid the feeling ... When Ortho-K lenses are worn, the eyes are closed for sleep, although the same issues that accompany wearing contact lenses ...
Cosmic microwave background
Gravitational lensing. The second type of B-modes was discovered in 2013 using the South Pole Telescope with help from ... Lewis, A.; Challinor, A. (2006). "Weak gravitational lensing of the CMB". Physics Reports. 429: 1-65. arXiv:astro-ph/0601594 . ... Instead they can be created by two mechanisms: the first one is by gravitational lensing of E-modes, which has been measured by ... This artist's impression shows how light from the early universe is deflected by the gravitational lensing effect of massive ...
Main article: Close-up lens. A close-up lens is not technically a filter but accessory lens which attaches to a lens like a ... The filter diameter for a particular lens is commonly identified on the lens face by the ⌀ symbol. For example, a lens marking ... A few lenses, such as some of Canon's L series lenses, require the use of a filter to complete their weather sealing. ... A close-up lens is a single or two-element converging lens used for close-up and macro photography, and works in the same way ...
Heat shock protein
Lens. Alpha crystallin (α4- crystallin) or hspb4 is involved in the development of lens in Zebrafish as it is expressed ... Expression of the hspb4 gene, which codes for alpha crystallin, increases considerably in the lens in response to heat shock.[ ... hspb1 (HSP27) is expressed during stress and during the development of embryo, somites, mid-hindbrain, heart and lens in ...
Harold Ridley (ophthalmologist)
This led him to propose the use of artificial lenses made of Perspex in the eye, to treat cataract. He had a lens manufactured ... The first US Food and Drug Administration (FDA) approved lenses, (Choyce Mark VIII and Choyce Mark IX Anterior Chamber lenses) ... although it was not until 8 February 1950 that he left an artificial lens permanently in place in an eye. The first lens was ... was an English ophthalmologist who invented the intraocular lens and pioneered intraocular lens surgery for cataract patients.[ ...
Corrective lenses for myopia have negative powers because a divergent lens is required to move the far point of focus out to ... Strongly near-sighted wearers of contact lenses do not experience these distortions because the lens moves with the cornea, ... contact lenses, or surgery. Eyeglasses are the easiest and safest method of correction. Contact lenses can provide a ... of the crystalline lens as a result of sorbitol accumulating in the lens. This edema often causes temporary myopia. ...
NASA spinoff technologies
Scratch-resistant lenses. A sunglasses manufacturer called Foster Grant first licensed a NASA technology for scratch- ... resistant lenses, developed for protecting space equipment from scratching in space, especially helmet visors. ...
Contact lens solution. A contact lens solution containing polyaminopropyl biguanide in combination with a borate buffer ... "Comparative study of the microbial flora on contact lenses, in lens cases, and in maintenance liquids". Contact Lens and ... is a disinfectant and a preservative used for disinfection on skin and in cleaning solutions for contact lenses.[citation ... and fungicidal activity at low concentrations coupled with very low toxicity when used with soft-type contact lenses. ...
Glossary of video terms
The largest lens opening (smallest f-number) at which the lens can be set. A fast lens transmits more light and has a larger ... The CS-mount description applies to both lenses and cameras. CS-mount lens cannot be put on C-mount cameras. C-mount lenses can ... Lens Speed. The ability of a lens to transmit light, represented as the ratio of the focal length to the diameter of the ... Focal Length (of a lens). The distance from the focal point to the principal point of the lens. The focal length is ...
... is also used in some contact lens solutions. Derivatives. *Taurine is used in the preparation of the anthelmintic ... In cosmetics and contact lens solutions. Since the 2000s cosmetic compositions containing taurine have been introduced, ...
During frost heave, one or more soil-free ice lenses grow, and their growth displaces the soil above them. These lenses grow by ... This effect allows water to percolate through the soil towards the ice lens, allowing the lens to grow. ... Yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as 1 foot (0.30 metres) or more ... Another water-transport effect is the preservation of a few molecular layers of liquid water on the surface of the ice lens, ...
Types of lenses and screens. Spherical. Most motion picture lenses are of the spherical variety. Spherical lenses ... A special anamorphic lens is used on the camera to compress the image, and a corresponding lens on the projector to expand the ... Projector lenses differ in aperture and focal length to suit different needs. Different lenses are used for different aspect ... the spherical lens is the most common and versatile projection lens type. ...
Pellucid marginal degeneration
Contact lenses. The early stages of pellucid marginal degeneration may also be managed with soft contact lenses. ... Most of these lenses are in the range of 15.5mm to 18.0mm in diameter. Regardless of the lens size, it is thought that the ... New studies found that the use of Scleral contact lens, a type of rigid gas permeable (RGP) lens, may be a good option for most ... and at times more comfortable than soft lenses, regardless of the fact that it is a rigid lens. The highlight to the scleral ...
Lighthouse of Cabo de São Vicente
The beacon itself has operated with a hyper-radiant Fresnel lens (larger than 1st order) since 1908, with a focal plane of 86 ... Fresnel lens, making it one of the largest optics used in Portuguese lighthouses and one of the 10 largest in the world. It ...
Corrective lenses can be produced in many different shapes from a circular lens called a lens blank. Lens blanks are cut to fit ... "BluTech Lenses - Technology, The story behind BluTech Lenses". BluTech Lenses.. *^ "Expert Healthy Vision & Eye Care Tips, News ... Higher power lenses can cause distortion of peripheral vision and may become thick and heavy if a large lens shape is used. ... For example, sunlenses could be easily lifted up and down while mixed with myopia lenses that always stay on. Presbyopia lenses ...
Dual (grammatical number)
"two lenses"). שמיים shamáyim ("sky"). מספריים misparáyim ("scissors"). Khoe languages. In Nama, nouns have three ...
List of vegetables used in Assamese cuisine
Lens culinaris. Motor mah. Pea. Pisum sativum. Dhoa mogu. White lentil. Vigna mungo. ...
optical lenses. *a program for Los Alamos National Laboratory. *tables for LORAN navigation ...
Contact lenses. Use in whole grain breads. Agricultural Research Service scientists are investigating using the plant- ...
... are a clouding of the lens of the eye, causing blurry vision. They are a common and even normal part of aging, but ... The lens of your eye consists mostly of protein and water. The lens is located behind your pupil and iris (the black and ... The proteins in your lens are arranged in a way that keeps the lens clear. But due to normal changes that occur with age, these ... Surgery to replace the lens in your eye with an artificial lens is the only way to remedy a cataract. But its rarely necessary ...
Refractive Lens Exchange or Lens Replacement Surgery
Brian Boxer Wachler says refractive lens exchange or clear lens extraction may be better than LASIK for presbyopia and ... Contact Lenses * Soft Contacts Featured. Contact Lens Basics Reading a Contact Lens Prescription Soft Contact Lens Care View ... Eyeglass Lenses Featured. How to Choose Eyeglass Lenses Anti-reflective Lenses Progressive Lenses View all ... Refractive lens exchange, also called lens replacement surgery or clear lens extraction, may be a better option than LASIK, PRK ...
Halloween: Contact Lenses
Get a Halloween-themed social media graphic about contact lens emergency supplies. ... Keep a close eye on your #emergency supplies & avoid a nightmare eye infection! If you wear contact lenses, #PrepYourHealth ... with a contact lens case, disinfecting solution, & a backup pair of glasses: http://ow.ly/rU4a30pJheIexternal icon # ...
Announcements | Contact Lenses | CDC
Healthy and Safe Contact Lens Cleaning and Use. Millions of people use contact lenses every day but lens cleaning practices can ... Hands should be washed before handling contact lenses and contacts should be properly cleaned, disinfected, and stored to ... Following your eye doctors recommendations and a few simple steps can lead to healthy daily contact lens use. ... Contact Lens, Lens Care Systems, & Solution Typesplus icon *Contact Lens Types ...
Eyeglass Lenses | Kodak
Glasses and Contact Lenses
When this happens, people wear glasses or contact lenses. Find out more in this article for kids. ... But eyeglasses or contact lenses, also called corrective lenses, can help most people see more clearly. ... Glasses or contact lenses correct vision because they allow the eye to focus light in the right spot on the retina - the spot ... Glasses or contact lenses work so well because they can correct refractive problems. In other words, they bend the light rays ...
ZEISS Lens Gears make ZEISS Otus, ZEISS Milvus and ZEISS Loxia lenses a proper cine-style lens for professional filmmakers. The ... This means the inner diameter can be reduced according to the lens diameter, thus supporting multiple lenses. The GumGum also ... ZEISS Loxia lenses are suitable for digital Sony Alpha cameras and have been optimized for film and sensors up to full 35 mm ... The lenses offer a high resolution across the entire image field and - especially at the maximal aperture opening of f/2 - a ...
Progressive Lens solutions Whatever our eyes need in todays world - ZEISS provides the right progressive lenses solution. ... In addition, we are proud to offer a complete portfolio of ZEISS-branded stock lenses. These lenses come in a large assortment ... All freeform products by Carl Zeiss Vision, including ZEISS lenses. *Semi-finished lenses, such as GT2 by ZEISS, Flat Top 28, ... Having the option to finish lenses in-house can be an important factor in remaining competitive. ZEISS stock lenses meet your ...
Slideshow: Permanent Lenses in Sight | WIRED
... implantable lens that can help even the most nearsighted patients. The images show a surgeon implanting the lens through a 3 ... The Verisyse lens corrects moderate to high nearsightedness. A surgeon positions it over the pupil between \[…\] ... The Verisyse lens, made my Advanced Medical Optics, is racing STAAR Surgical neck and neck for the first FDA approval of a ... Slideshow: Permanent Lenses in Sight. credit Image courtesy STAAR Surgical. FDA approval is imminent for a permanent, ...
Global Contact Lenses and Solutions Industry
This report analyzes the worldwide markets for Contact Lenses and Solutions in US$ Million by the following Segments:... ... Daily Wear Lenses Daily Wear Hard Lens Daily Wear Soft Lens Daily Wear Hard Gas-Permeable Lens Extended Wear Lenses Soft Lenses ... Contact Lenses Rigid Gas-Permeable Lenses Soft Contact Lenses Spherical Lenses Toric Lenses Multifocals Hybrid Contact Lenses ... Hard Lenses PMMA Lenses Rigid Gas-Permeable Lenses Advantages Disadvantages Soft Lenses Description Spherical Soft Lenses ...
Lens photography | Understanding camera lenses | Adobe
Lens photography starts with choosing the right camera lens and knowing that different focal lengths, from wide-angle to ... Nifty fifty lenses. Nifty fifty is a nickname for a 50mm lens that has a wide aperture. The lens elements on a nifty fifty are ... Lenses that come with cameras.. Camera bodies are often sold in combination with a lens. These are called kit lenses. They are ... How to choose a lens.. The right lens for you depends on what type of photography you want to shoot. And your lens decision ...
Contact lens - Wikipedia
"Coloured Contact Lenses". lenses-contact.co.uk.. *^ "How Do You Find the Right Circle Lens?". EyeCandys. Retrieved 26 March ... "Soft Contact Lens Care Products".. *^ www.feelgoodcontacts.com. "Caring For Contact Lenses - Feel Good Contact Lenses". www. ... the FDA labels non-corrective cosmetic contact lenses as decorative contact lenses. Like any contact lens, cosmetic lenses ... "International Contact Lens Prescribing in 2010". Contact Lens Spectrum. October 2011. *^ Agarwal, R. K. (1969), Contact Lens ...
Camera lens - Wikipedia
A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in ... Lens mounts. Main article: Lens mount. Many single-lens reflex cameras and some rangefinder cameras have detachable ... Lenses for aerial photography.. *Fisheye lenses: extreme wide-angle lenses with an angle of view of up to 180 degrees or more, ... Today, most lenses are multi-coated in order to minimize lens flare and other unwanted effects. Some lenses have a UV coating ...
SEL1635Z | α Lenses | | Sony TN
Lens hood (ALC-SH134: petal shape, bayonet type), Lens front cap, Lens rear cap, Case ... The lens combines five aspherical elements (including one AA - advanced aspherical lens), with 3 ED (Extra-low Dispersion) ... A 16mm to 35mm wide-angle zoom range coupled with effective built-in optical image stabilization makes this lens an excellent ... Reliable operation in a variety of conditions is ensured by a design that prevents dust and moisture from entering the lens. ...
SELP18105G | α Lenses | | Sony IQ
A lever and ring on the lens barrel allow zoom speed to be freely adjusted as required while maintaining a sure, stable grip. ... This G Lens for E-mount cameras delivers stunning still or movie imagery with the flexibility of 6x power zoom. Maximum ... Lens hood (ALC-SH128: petal shape, bayonet type), Lens front cap, Lens rear cap ... One lens for diverse shooting needs. Having to change lenses as you shoot can slow you down and introduce unwanted changes in ...
SEL24F18Z | α Lenses | | Sony TZ
... prime lens features a large F1.8 maximum aperture and is capable of outstanding sharpness and contrast throughout the frame ... Lens hood (ALC-SH114: petal shape, bayonet type), Lens front cap, Lens rear cap, Case ... Spectacular ZEISS prime lens performance. This first-class 24mm (35mm full frame equivalent) prime lens features a large F1.8 ... With a 16-cm minimum focusing distance this lens makes it possible to get close to your subject in 1:4 macro shots that show ...
Lumix G Lenses | Panasonic Australia
... which are world renowned LEICA Quality Lenses developed and manufactured by industry-leading technologies. ... Learn more about our revolutionary Lumix G Lenses, ... LUMIX Camera Lenses Video Cameras Camera Accessories Home ... Micro Four Thirds Interchangeable Lens, Standard Zoom, POWER O.I.S., Dual I.S.2 Compatible, High-Speed AF, Rugged Design. ... Micro Four Thirds 25mm Fixed Focal Length Lens / 50mm (35mm camera equiv.) High-Speed AF, Rugged Design. ...
Contact Lenses and Eye Infections
... Articles OnContact Lenses. Contact Lenses Contact Lenses - Contact Lenses and Eye Infections ... Slideshow: Contact Lens Tips Contact lenses are a convenient and comfortable alternative to eyeglasses for many people. But you ... Make sure you clean and disinfect your lenses and lens case correctly, and dont keep either longer than you should. ... Dont throw your lenses away. Put them in the case, and bring them when you see your eye doctor. They may give him or her a ...
Lenses We Offer
Thinner, flatter lenses are recommended when a prescription is strong. Flatter lenses enhance lens appearance by reducing edge ... Some materials, such as Phoenix lenses, high-index lenses and several new plastic lens types come standard with scratch ... Tinted lenses can be tinted from light to very dark. Tints for sun lenses are usually medium to dark shades, and can either be ... Lens Treatments. Photochromic lenses darken and lighten according to light exposure. If the wearer is in the sun, they get ...
With a large lens, we have more room for error around the edges as we refine our procedure. We used this lens positive to make ... We have concluded that the best way to produce a lens using epoxy resin is to 3D print the lens positive, wrap it in plastic ... We 3D printed a "lens positive", a piece of opaque plastic in the shape of our desired lens. This time we were careful to print ... The ability to simply print out a lens without intermediate steps would be enormously useful in bringing down the costs of lens ...
Camera Lenses & Filters for sale | eBay
Get the best deals on Camera Lenses & Filters when you shop the largest online selection at eBay.com. Free shipping on many ... What are camera lens filters for?. Lens filters are used for protecting the front element of a lens. They are used for outdoor ... Zeiss 21mm F2.8 Distagon T* ZE Lens 21/2.8 Canon EF With Lens Hood. $588.00 ... A filter adapter ring is a device that is used when a filter is being used on a lens with a larger or smaller thread size. The ...
H-HS12035 Lumix G Lenses - Panasonic
POWER O.I.S. : Micro Four Thirds Lenses, Standard Zoom Lens ... Lumix G Lenses. LUMIX G X VARIO 12-35mm / F2.8 ASPH. / ... UED (Ultra Extra-Low Dispersion) Lens. UED (Ultra Extra-Low Dispersion) lens minimize chromatic aberration while the UHR (Ultra ... Micro Four Thirds 12-35mm Standard Zoom Lens / 24-70mm (35mm camera equiv.) ... by applying the extra-low refractive index coating with nano-sized structure on the surface of the lens. It results in super ...
Exclusive: Mojo Vision's AR contact lenses
At first the lenses will be powered by a tiny thin-film, solid-state battery within the lens. Sinclair says the battery is ... Lenses for consumers, eventually. Only after Mojo has begun marketing its vision assistance and vertical market lenses does it ... "Weve tested pretty much everything outside the lens, and now its all getting pulled together in the lens," says Sinclair. ... the normal loss of ability to focus the lens of the eye on small objects that comes with aging. The Mojo lenses, for example, ...
Panasonic lenses firmware upgrade announced | TechRadar
... allowing for seven new lenses to be added to the video line-up. ... announced a new firmware upgrade for its Lumix G series lenses ... The lenses that can be added to the video line-up now include the 14mm pancake lens, the 8mm fisheye lens and the 45-200mm zoom ... Panasonic has announced a new firmware upgrade for its Lumix G series lenses, allowing for seven new lenses to be added to the ... and means the following lenses can now be considered as part of the HD Lenses of Lumix G Micro System line-up:. Lumix G 14mm f/ ...
Specialty Contact Lenses | Walgreens
View current promotions and reviews of Specialty Contact Lenses and get free shipping at $35. ... Clear eyes Contact Lens Relief Soothing Eye Drops. (. .5 fl oz. ). Clear eyes Contact Lens Relief Soothing Eye Drops. Compare. ... Refresh Contacts Contact Lens Comfort Moisture Drops for Dry Eyes. (. .4 fl oz. ). Refresh Contacts Contact Lens Comfort ... Opti-Free Express Contact Lenses Rewetting Drops. (. .33 fl oz. ). Opti-Free Express Contact Lenses Rewetting Drops. Compare. ...
CooperVision Contact Lenses | Walgreens
All lenses:Biofinity,Biofinity Toric,Proclear,Biomedics 55,Avaira,Vertex,Frequency 55 aspheric,proclear compatibles,biomedics ... Coopervision contact lenses at Walgreens.com! Free shipping, FSA, daily promotions! ... Look for any rips or tears in the lens. Dont use a lens that is damaged in any way. To insert the lens, use the index finger ... Color lenses change the color of the eyes while correcting vision, while toric lenses are made for people with an eye condition ...
Intraocular Lenses - Mayo Clinic
Lenses - SlashGear - Page 7
Lenses. Sony Lens Cameras QX10 and QX100 manuals leak in hardware detail. Chris Burns , Aug 16, 2013 ... Sigma has unveiled a handful of new lenses that will join the companys current lineup of Art lenses, which are designed to be ... In late January, Sigma unveiled several new lenses in the companys Art line. When the company announced those new lenses in ... The four new lenses that Sigma announce are a 30mm f/1.4 DC HSM, 60mm f/2.8 DN, 30mm f/2.8 DN, and a 19mm f/2.8 DN. ...
50mmReading glassesAsphericBifocalWear contact lenses2017Aspherical lensesCorneaDiameterZEISSWearersAperturePrime LensesIntraocular lensDSLRInterchangeableWide-angleOpticianCorrectionCorrectsLEICAF2.8Soft Contact LensesToric contact lensesMultifocal contact lensesFocal lengthsChromatic aberrationExtra-low DispersionZoom LensesBends lightLead to cornealAdaptorEyeglassCorneal ulcersRefractive ErrorsGlasses and Contact LensesFisheye lensSpherical LensesOpticsFujifilmEyeglassesAutofocus LensesTelephoto lensesConvexImage StabiliserIndex of refract300mmDisinfectAstigmatismNearsightednessContact lens wearProper contact lensDecorative contact lensesCameraIOLsBifocalsMacro lensDisposable contact lenses
- Nifty fifty is a nickname for a 50mm lens that has a wide aperture . (adobe.com)
- Micro Four Thirds 25mm Fixed Focal Length Lens / 50mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 10-25mm Standard Zoom Lens / 20-50mm (35mm camera equiv. (panasonic.com)
- Learn about topics such as How to Repair Lens Problems on Your Digital Camera , How to Shoot with a 50mm Lens , How to Clean a Camera Lens , and more with our helpful step-by-step instructions with photos and videos. (wikihow.com)
- With a standard 50mm focal length on full-frame cameras, this is an unbeatable choice for photographers who love to work with prime lenses, and a perfect starting point for a superb ZEISS lens collection. (sony.co.uk)
- Refractive lens exchange (RLE) replaces your eye's clear natural lens with an artificial intraocular lens (IOL) to correct your refractive error and achieve sharper focus, reducing your need for reading glasses or bifocals . (allaboutvision.com)
- Non-surgical options for presbyopia include reading glasses, bifocal or progressive lenses , and multifocal contact lenses . (allaboutvision.com)
- Presbyopia historically has been corrected with prescription glasses with bifocal or progressive lenses or by reading glasses. (nationalpost.com)
- It is often managed with prescription glasses with bifocal or progressive lenses or by reading glasses over contact lenses. (nationalpost.com)
- Alcon Dailies Total1 ® contact lenses, are single-use multifocal lenses that became available in Canada last year, giving patients with presbyopia a comfortable alternative to burdensome reading glasses. (nationalpost.com)
- The Moment Wide 18mm Lens is a stunning aspheric lens for your iPhone camera that delivers exceptional edge-to-edge image quality. (apple.com)
- He explains that, with Alcon Dailies Total1 ® multifocal contact lenses, the near-vision correction is addressed at the centre of the lens and that its aspheric design means that the power gradually blends toward the distance. (nationalpost.com)
- Aspheric lenses are also useful for high prescriptions. (encyclopedia.com)
- Manufacture of integrated lens arrays, microlens arrays, aspheric lenses and condenser lenses by glass molding. (photonics.com)
- THURSDAY, Aug. 13, 2020 (HealthDay News) -- Kids suffering from nearsightedness can slow the progression of their myopia by using soft bifocal contact lenses , a new trial shows. (webmd.com)
- High-powered bifocal contacts effectively slowed the progression of nearsightedness, while medium-powered bifocal contacts and single-focus lenses did not. (webmd.com)
- The high-powered bifocal lenses also did not appear to hurt kids' vision, even though they were subjected to stronger reading power before they needed that level of correction, the researchers said. (webmd.com)
- When testing kids' ability to read gray letters on a white background, there was a two-letter difference between children wearing single-vision lenses and those with bifocal contacts. (webmd.com)
- Multifocal lenses improve both near and distant vision and are suitable for individuals who require bifocal eyeglasses. (walgreens.com)
- Special therapeutic, bifocal and cosmetic contact lenses also are available. (mayoclinic.org)
- Some patients may also use bifocal or multifocal lenses to correct both long sightedness and short sightedness. (news-medical.net)
- They may have the option to wear bifocal contact lenses that are split into distant vision at eye level and near sight at the lower level. (news-medical.net)
Wear contact lenses7
- People choose to wear contact lenses for many reasons. (wikipedia.org)
-  Others wear contact lenses for functional or optical reasons. (wikipedia.org)
- People who wear contact lenses have a higher risk for keratitis, an infection of the cornea , the clear outer covering of your eye . (webmd.com)
- Many who wear contact lenses prefer the colored version for a variety of reasons, including the fact that they are easy to see when out of the eye. (emory.edu)
- People allergic to certain plastics should not wear contact lenses or eyeglass frames or lenses manufactured from that type of plastic. (encyclopedia.com)
- They can also be a factor in headaches for people who wear contact lenses if they are wearing the wrong prescription. (news-medical.net)
- Should You Wear Contact Lenses for Astigmatism? (mercola.com)
- The week of August 21-25, 2017 marks the fourth annual Contact Lens Health Week ! (cdc.gov)
- Two SLD elements, one Glass Mold Aspherical plus two Hybrid Aspherical lenses provide excellent correction of various aberrations and a high level of optical performance. (dpreview.com)
- Two SLD elements and four aspherical lenses provide the ultimate correction against distortion as well as all types of aberration, especially spherical aberration. (dpreview.com)
- The use of aspherical lenses in the construction of this lens not only corrects aberrations but also produces a very small and lightweight lens design. (dpreview.com)
- The lens is located behind your pupil and iris (the black and colored areas of your eye), which are covered by your cornea (the clear outer layer of your eye). (everydayhealth.com)
- Contact lenses appear to be worn in direct contact with the cornea, but they actually float on a layer of tears that separates them from the cornea. (encyclopedia.com)
- Scleral contact lenses can help people who don't respond to other treatments for their cornea conditions. (mayoclinic.org)
- A fluid barrier keeps the scleral lens from touching the cornea. (mayoclinic.org)
- The lack of contact between the back of the scleral lens and the cornea reduces pain, and the spherical front surface of the lens improves vision. (mayoclinic.org)
- Scleral contact lenses cover the white part of the eye and arch over the cornea. (mayoclinic.org)
- This is when light entering a person's eyes through the outer cornea of the eye and through the lens does not focus on the retina but either converges before or after the retina. (news-medical.net)
- Wearers may use the contact lenses to help correct astigmatism which impairs clarity in vision due to an uneven eye lens or cornea. (news-medical.net)
- contact lens Lens worn on the cornea to aid defective vision. (encyclopedia.com)
- Hard (corneal) lenses cover the pupil and part of the cornea. (encyclopedia.com)
- Soft (hydrophilic) lenses cover the whole cornea and are hydrated in saline solution. (encyclopedia.com)
- A cylindrical lens can help you overcome the visual impairment of astigmatism, a condition in which the front surface of the cornea of the eye is not truly spherical. (innerbody.com)
- They have a design feature that allows the lens to rotate and adjust to the proper orientation on the cornea, allowing the power meridians of the lens to align with the appropriate eye meridians, giving the wearer clear vision. (mercola.com)
- Rigid gas permeable (RGP or GP) contact lenses - These lenses, as their name implies, are rigid, allowing them to retain their spherical shape on the eye, as opposed to conforming to the irregular shape of the cornea. (mercola.com)
- Surgical ways include corneal procedures (i.e., laser surgery on the cornea, thermokeratoplasty, and implantation of corneal inlays) and intraocular procedures that include cataract surgery or refractive lens exchange with the implantation of multifocal intraocular lenses or monofocal lenses with refractive target monovision. (hindawi.com)
- This means the inner diameter can be reduced according to the lens diameter, thus supporting multiple lenses. (zeiss.com)
- While the overall length of the different Loxia lenses might vary, the front diameter is consistent for all three focal lengths in the family. (zeiss.com)
- These lenses were made from heavy blown glass and were 18-21 mm (0.71-0.83 in) in diameter. (wikipedia.org)
- We started by 3D printing molds for convex lenses 1 inch in diameter with a 10 cm focal length. (princeton.edu)
- We aimed for a larger lens, 2 inches in diameter, because we had trouble working with the smaller lens earlier. (princeton.edu)
- The intraocular lens is designed with specific flexibility characteristics so as to exhibit greater than approximately 1.0 mm axial displacement of the optic portion along the eye's optical axis under a compression force suitable to effect a 1.0 mm in diameter compression of the intraocular lens. (google.com.au)
- Light and inconspicuous - the ZEISS Loxia Lenses are optimally suited to video recordings: their compact size enables the cameraman to work unobtrusively from various angles and thus avoid disrupting the scenery. (zeiss.com)
- The ZEISS Loxia lenses are small, robust and made of metal. (zeiss.com)
- A harmonious bokeh and the full-frame coverage are the ideal complements to the ZEISS Loxia lenses. (zeiss.com)
- ZEISS Lens Gears make ZEISS Otus, ZEISS Milvus and ZEISS Loxia lenses a proper cine-style lens for professional filmmakers. (zeiss.com)
- The ZEISS Lens Gears are available in four different sizes: mini, small, medium and large. (zeiss.com)
- ZEISS Loxia lenses are suitable for digital Sony Alpha cameras and have been optimized for film and sensors up to full 35 mm format (24 x 36 mm). (zeiss.com)
- With their reliable functions, camera lenses from ZEISS ensure that photographers can fully concentrate on the image and composition, and bring their creativity to life. (zeiss.com)
- ZEISS grants a warranty period of two years from the date of purchase for all its photographic lenses. (zeiss.com)
- ZEISS stock lenses meet your needs by combining industry-leading precision and quality with great value. (zeiss.com)
- With same-day* order fulfillment and first-rate customer service, ZEISS stock and uncut lenses will meet your needs and those of your patients. (zeiss.com)
- The entire ZEISS Rx portfolio is available as uncut lenses, providing you with the customized lenses your patient needs. (zeiss.com)
- In addition, we are proud to offer a complete portfolio of ZEISS-branded stock lenses. (zeiss.com)
- These lenses come in a large assortment of materials, treatments, and powers, giving you the ability to have ZEISS stock on hand in your office or to order on-demand. (zeiss.com)
- ZEISS stock and uncut lenses are manufactured to meet the high quality standards you expect from ZEISS. (zeiss.com)
- The ZEISS National Lab Network offers a wide selection of stock and uncut lenses. (zeiss.com)
- With outstanding performance, the highest quality optics, and great value, ZEISS stock and uncut lenses meet the needs of every patient and practice. (zeiss.com)
- For a detailed list of stock and uncut lens availability, please download the ZEISS Stock Lens Portfolio PDF. (zeiss.com)
- ZEISS is one of the world's leading manufacturers of eyeglass lenses, and is committed to delivering maximum precision and comfort. (zeiss.com)
- ZEISS designs and produces lenses, instruments and measurement systems, as well as retail concepts and technology services that continue to raise the bar in vision care. (zeiss.com)
- This week the team at ZEISS have announced that they'll no longer be branding their lens family with the name of their founder. (slashgear.com)
- ZEISS lenses are known for their superior sharpness, contrast, and well-defined blacks. (sony.co.uk)
- The Master Anamorphic Lenses have been co-developed by ARRI and ZEISS, are manufactured by ZEISS, and are sold exclusively by ARRI. (arri.com)
- Increasing awareness about the importance of proper contact lens hygiene can encourage wearers to adopt healthy habits that can help reduce their chances of getting an eye infection. (cdc.gov)
-  As of 2010 [update] , the average age of contact lens wearers globally was 31 years old, and two-thirds of wearers were female. (wikipedia.org)
- Contact lens wearers can also wear sunglasses, goggles, or other eyewear of their choice without having to fit them with prescription lenses or worry about compatibility with glasses. (wikipedia.org)
- Contact lens wearers may suffer from headaches due to different factors. (news-medical.net)
- Wearers have to make sure that the toric lens sits on the eye in a specific position. (news-medical.net)
- Contact lens wearers can also suffer from dry eyes, also known as keratoconjunctivitis sicca, when not enough tears are made in the tear ducts. (news-medical.net)
- Contact lens wearers can use eye drops to lubricate their eyes and alleviate the symptoms. (news-medical.net)
- However, contact lens wearers are at risk for contact lens-related eye infections, especially when wearers do not practice proper contact lens wear and care habits. (medscape.com)
- Health education measures directed toward contact lens wearers should emphasize raising awareness of the risks of sleeping in contact lenses as well as adherence to all recommendations for the wear and care of contact lenses. (medscape.com)
- [ 2 ] Among the many behaviors that increase the risk for a contact lens-related corneal infection, sleeping in lenses is one of the riskiest and one of the most commonly reported behaviors among adolescent and adult contact lens wearers. (medscape.com)
- [ 3 ] Approximately one third of contact lens wearers report sleeping or napping in their lenses. (medscape.com)
- Contact lenses prescribed by a licensed doctor of optometry are worn safely and comfortably by millions of people worldwide and have a long history of providing wearers with a safe and effective form of vision correction. (aoa.org)
- The lenses offer a high resolution across the entire image field and - especially at the maximal aperture opening of f/2 - a harmonious bokeh in the background. (zeiss.com)
- Almost any lens in the mid-range with a wide aperture will allow you to take stylized portraits with a shallow depth of field. (adobe.com)
- An 85mm is known as a portrait lens, and one with a wide aperture can capture that shallow depth of field and separation from the subject and background," says Diaz. (adobe.com)
- As shown, a pinhole "lens" is simply a small aperture that blocks most rays of light, ideally selecting one ray to the object for each point on the image sensor. (wikipedia.org)
- This first-class 24mm (35mm full frame equivalent) prime lens features a large F1.8 maximum aperture and is capable of outstanding sharpness and contrast throughout the frame plus beautiful "bokeh" in out-of-focus areas. (sony.com)
- I often adjust the exposure for DOF, or to be where I want with the lens' aperture, but I don't have a lot of time to set up each shot. (cambridgeincolour.com)
- They are the APO Macro 150 mm F2.8 EX DG HSM (a fast tele-macro lens with a Hyper Sonic Motor), the 24-70 mm F2.8 EX DG Macro (a useful 24 mm wide angle zoom with a large maximum aperture and macro capabilities) and the 28-70 mm F2.8 EX DG (a compact standard wide angle zoom with a large maximum aperture). (dpreview.com)
- This large aperture telephoto macro lens enables you to shoot up to 1:1 life size close-ups. (dpreview.com)
- Its large F2.8 aperture makes it an ideal lens for digital SLR as well as film SLR cameras. (dpreview.com)
- From 24mm super wide angle to 70mm medium telephoto, this lens provides a large F2.8 aperture at all focal lengths. (dpreview.com)
- This is the world's smallest, large and constant aperture zoom lens and is ideal for digital SLR cameras. (dpreview.com)
- A unique feature of the Tair 11 series is the twenty aperture blades, far more than many modern lenses. (wikipedia.org)
- The AF-S NIKKOR 28mm f/1.4E ED is the latest in the Gold Ring Series of f/1.4 prime lenses. (nikonusa.com)
- Some lenses are "fixed" (also known as prime lenses) and have a single focal length, while others are "variable" (also known as zoom lenses) and can adjust to different focal lengths. (adobe.com)
- The Master Anamorphic series, a range of nine high-performance prime lenses, represents a significant step forward in the technology and practicality of anamorphic cinematography for 35 format digital and film cameras. (arri.com)
- Tair is the name of a series of prime lenses manufactured by KMZ in the Soviet Union. (wikipedia.org)
- The artificial intraocular lens is a permanent replacement for your natural lens and is designed to last the rest of your life. (allaboutvision.com)
- An accommodating intraocular lens including an optic portion having an outer peripheral edge and two, three or four balanced haptic elements for use to achieve multifocal refractive correction. (google.com.au)
- 2. The intraocular lens of claim 1 wherein the haptic elements and the optic portion are both formed of a foldable or compressible material. (google.com.au)
- 3. The intraocular lens of claim 1 wherein said lens is formed from a material selected from the group consisting of silicone polymers, hydrocarbon and fluorocarbon polymers, hydrogels, soft acrylic polymers, polyester, polyamides, polyurethane, silicone polymers with hydrophilic monomer units, fluorine-containing polysiloxane elastomers and combinations thereof. (google.com.au)
- 4. The intraocular lens of claim 1 wherein said lens is formed from a hydrogel material. (google.com.au)
- 5. The intraocular lens of claim 1 wherein said lens is formed from a hydrogel material which is 18 percent by weight water. (google.com.au)
- 6. The intraocular lens of claim 1 wherein said lens is formed from poly(HEMA- co -HOHEXMA). (google.com.au)
- 7. The intraocular lens of claim 1 wherein said lens is formed from a material having a refractive index above 1.33. (google.com.au)
- 10. The intraocular lens of claim 1 wherein said haptic elements are formed with a dimension in a plane generally perpendicular to the eye's optical axis to be greater than or equal to a dimension in a plane generally parallel to the eye's optical axis. (google.com.au)
- 11. The intraocular lens of claim 1 wherein a glare reduction zone is formed adjacent to the outer peripheral edge of the optic portion. (google.com.au)
- 12. The intraocular lens of claim 1 wherein one or more of said haptic elements includes a stiffening element having less resistance to bending in a plane generally parallel to the eye's optical axis than in a plane generally perpendicular to the eye's optical axis. (google.com.au)
- 13. The intraocular lens of claim 1 wherein one or more of said haptic elements includes a stiffening element formed from a material selected from the group consisting of polyimide, polyolefin, high-density polyester, nylon and metal. (google.com.au)
- In the attempt to manage presbyopia, different intraocular lens designs have been proposed such as monofocal IOLs with monovision or multifocal IOLs. (hindawi.com)
- It has been attributed to several factors such as the pupil size, total and corneal aberrations, degrees and axis of astigmatism, potential of visual perception, and axial movement of the intraocular lens. (hindawi.com)
- Whether you use film cameras, DSLR cameras, or mirrorless cameras, you will encounter a similar range of available focal lengths in your lenses. (adobe.com)
- The lens combines five aspherical elements (including one AA - advanced aspherical lens), with 3 ED (Extra-low Dispersion) glass elements to deliver high-precision shots and breathtaking rendering - without the bulky design usually associated with similar DSLR lenses. (sony.com)
- Ensure that your DSLR camera produces the sharpest autofocus photos possible by calibrating your lens. (adobe.com)
- However, in a DSLR camera , an autofocused image requires clear communication between the lens (which lets in the light), the camera's autofocus chip (which determines when the image is in focus) and the camera's sensor (which creates the image). (adobe.com)
- I wish to convert to a decent DSLR and at present own a Pentax SFXn camera with numerous lenses. (ephotozine.com)
- Do you have a camera dealer close to you where you can take a couple of your lenses along and try them on a Pentax dSLR body. (ephotozine.com)
- I only have one DSLR right now so the bridge camera serves as my wide angle lens. (cambridgeincolour.com)
- It's the whole reason why you buy a dslr, for the ability to change out the lenses to best suit the dynamics of the image. (cambridgeincolour.com)
- Without a doubt the cameras which created the most 'buzz' in 2009 were the Olympus E-P1 and Panasonic GF1 - the first in a new breed of interchangeable-lens compacts that promise the image quality of a DSLR in a much more portable package. (dpreview.com)
- Interchangeable camera lenses. (adobe.com)
- But if you dip your toe into more advanced photography, you will likely work with a camera that has an interchangeable lens system. (adobe.com)
- Each interchangeable lens has a different focal length , which is good for different types of photography projects. (adobe.com)
- A lens might be permanently fixed to a camera, or it might be interchangeable with lenses of different focal lengths , apertures , and other properties. (wikipedia.org)
- Fujifilm has announced more details about upcoming accessories that will be available for the newly released interchangeable lens camera, the X Pro 1. (techradar.com)
- The X Pro 1 is Fuji's first interchangeable lens camera since 2006 and features an APS-C sized sensor which thanks to technology drawn from the firm's analogue heritage is apparently capable of out resolving a full-frame sensor. (techradar.com)
- In this buying guide we've rounded up all the current interchangeable lens cameras costing over $2500 and recommended the best. (dpreview.com)
- Prescriptions for contact lenses and glasses may be similar but are not interchangeable. (aoa.org)
- The Samsung NX10, another entry in the growing compact interchangeable-lens camera category, takes up less room in your camera bag than most DSLRs, while still featuring a 14.6 megapixel, APS-C, CMOS image sensor, 3-inch LCD, and the Samsung NX mount for interchangeable lenses. (macworld.com)
- Learn how to choose the right camera lens for your photography projects and how different focal lengths - from wide angle to telephoto - affect your images. (adobe.com)
- The lower the focal length of your lens, the wider its field of view - shorter focal lengths capture more wide-angle scenes. (adobe.com)
- Then you're going to need a wide-angle lens to fit everything in. (adobe.com)
- At the low end of the focal range spectrum are wide-angle lenses , typically 12mm to 35mm. (adobe.com)
- If you shoot landscapes, a variable wide-angle lens would support that type of photography," says photographer Pablo Diaz. (adobe.com)
- Wide-angle lenses - great for landscape photography, architecture photography, and photos of the sky or the Milky Way. (adobe.com)
- A 16mm to 35mm wide-angle zoom range coupled with effective built-in optical image stabilization makes this lens an excellent choice for snapshots, indoor scenes, group shots, landscapes, and more, especially with a full-frame α7 series body. (sony.com)
- With a 16-cm minimum focusing distance this lens makes it possible to get close to your subject in 1:4 macro shots that show detail with impressive wide-angle perspective. (sony.com)
- photography ) A wide-angle lens having an extremely wide field of view (approaching or exceeding 180 degrees) and producing images that are circular or distorted by curvature at the edges. (wiktionary.org)
- It's a perfect, everyday, go-to wide-angle lens for your mobile photography and filmmaking. (apple.com)
- If you're taking a close-up portrait, you might use a wide-angle lens . (howstuffworks.com)
- Through phone cases for the most popular brands, or a special clip for the others, you can now use their lenses (the macro, fisheye, wide-angle and telephoto) with any phone. (digital-photography-school.com)
- The first includes a macro, wide-angle and fish-eye lens. (digital-photography-school.com)
- If you decide you want to get a little further away the wide-angle lens is what you need. (digital-photography-school.com)
- The wide-angle lens will let you take photos at any distance. (digital-photography-school.com)
- The Struman wide-angle lens was attached to the phone and now you can see that there is a lot more room around the lighthouse. (digital-photography-school.com)
- Same Lighthouse, but with the wide-angle lens attached. (digital-photography-school.com)
- If you find that you don't want to get as close as you have to with the macro lens, put the wide-angle on and you can get that distance. (digital-photography-school.com)
- An optician makes or sells eyeglasses and contact lenses according to an ophthalmologist's or optometrist's prescription. (kidshealth.org)
- Patients who develop presbyopia will need to see their optician to get a new prescription for their contact lenses to help correct the condition. (news-medical.net)
- The patient will need to explore a better fitting toric lens with their optician. (news-medical.net)
- Bifocals provide both distance and near vision correction in one lens. (hopkinsmedicine.org)
- Contact lenses allow you to enjoy the benefits of clear vision without having to wear prescription eyeglasses and can simplify vision correction. (walgreens.com)
- Contact lenses offer numerous benefits for those who are in need of vision correction. (walgreens.com)
- The greater the index of refraction of the lens material and the greater the difference in the curvature between the two surfaces of the lens, the greater the change in direction of light that passes through it, and the greater the correction. (encyclopedia.com)
- Lenses can be unifocal, with one correction for all distances, or they can be correct for more than one distance (multifocal). (encyclopedia.com)
- however, lenses where the correction gradually changes from one area to the other, without visible lines, have been available since the 1970s. (encyclopedia.com)
- The ability of the lens to adjust from a distant to a near focus, called accommodation, gradually declines with age (a condition called presbyopia), often requiring correction. (britannica.com)
- The new lens power layout provides the ultimate correction against lateral chromatic aberration to which digital cameras are prone. (dpreview.com)
- Contact lenses, when worn and cared for properly, are a safe and effective form of vision correction used by an estimated 45 million Americans. (medscape.com)
- More particularly, the present invention relates to accommodating IOLs designed for refractive correction in aphakic eyes where a diseased natural lens is surgically removed, such as in the case of cataracts. (google.com.au)
- Safe contact lenses use provides an effective form of vision correction. (aoa.org)
- The Verisyse lens corrects moderate to high nearsightedness. (wired.com)
- Olloclip is one company that offers these types of lenses, and they've come out with an accompanying iPhone app that corrects distortion in photos created by the add-on lenses. (slashgear.com)
- the remainder of the lens corrects for distant objects (about 20 ft from the eyes). (encyclopedia.com)
- And lens calibration corrects how 'off' the lens is. (adobe.com)
- A prescription for contact lenses, therefore, involves more than simply knowing the optical power that corrects for nearsightedness, farsightedness, or astigmatism. (aoa.org)
- Anybody with existing Leica M lenses, or with a strong urge to buy some, will be pleased as it has been revealed that an M mount adaptor will be available. (techradar.com)
- Voigtlander 25mm VM F4 Color Skopar lens Leica fit, mint- Rangefinder coupled. (ebay.co.uk)
- Canon 100mm f3.5 Leica screw lens + case, hazy. (ebay.co.uk)
- Seeking to retain my trusted Nikon D300, but obtain even sharper, higher resolution images, I investigated the possible purchase of the top-price Nikkor17-55 f2.8G DX AFS IF-ED lens. (cambridgeincolour.com)
- Sigma Corporation is pleased to announce of the world's first High Speed Tele Macro MACRO 150mm F2.8 EX DG HSM lens. (dpreview.com)
- Sigma Corporation is pleased to announce the new 28-70mm F2.8 EX DG lens. (dpreview.com)
Soft Contact Lenses4
- d) Transmission spectra of pHEMA and commercial soft contact lenses when dipped into the dye. (nih.gov)
- We offer a wide variety of contact lenses, such as soft contact lenses, frequent replacement soft contact lenses and rigid, gas-permeable contact lenses. (mayoclinic.org)
- Toric contact lenses - These are soft contact lenses that are usually made of either the typical hydrogel material or a highly breathable silicone hydrogel. (mercola.com)
- You do not need to replace GP lenses as frequently as you do with soft contact lenses, but take note that these are custom-made as well, and can be pricier than toric lenses. (mercola.com)
Toric contact lenses2
Multifocal contact lenses5
- Mark Pennie relies on multifocal contact lenses to stay active on his motorcycle. (nationalpost.com)
- There is an alternative outside these traditional options: multifocal contact lenses. (nationalpost.com)
- Multifocal contact lenses feature power variations that allow for good vision from near to far and everything in between, all within one lens. (nationalpost.com)
- Multifocal contact lenses are useful for almost anyone," says Edmonton optometrist Dr. Michael Kim. (nationalpost.com)
- Adding that these multifocal contact lenses are "very exciting for the whole industry," he points out that, as well as being highly effective in terms of visual acuity, they score well because of their comfort, convenience and healthy properties. (nationalpost.com)
- My understanding is that the primary reson to get the DX lens over the FX lens was to get the extremely short focal lengths. (cambridgeincolour.com)
- The lens has a minimum focusing distance of 40cm (15.7 inches) at all focal lengths and is capable of macro photography with a maximum magnification ratio of 1:3.8. (dpreview.com)
- UED (Ultra Extra-Low Dispersion) lens minimize chromatic aberration while the UHR (Ultra High Refractive Index) lens realizes high descriptive performance from corner to corner. (panasonic.com)
- An advanced optical design that incorporates two ED (Extra-low Dispersion) glass elements and three aspherical elements offers enviable G Lens image quality throughout the zoom range. (sony.com)
- The people who will make your glasses for you need these numbers to create lenses that will correct the way your eye bends light. (kidshealth.org)
- This allows the pinhole to be opened up significantly (fourth image) because a thin convex lens bends light rays in proportion to their distance to the axis of the lens, with rays striking the center of the lens passing straight through. (wikipedia.org)
- In the last section, we saw that at any one point, a lens bends light beams to a certain total degree, no matter the light beam's angle of entry. (howstuffworks.com)
Lead to corneal2
- Contact lenses can lead to corneal ulcers and infections that are so severe that they cause blindness. (mercola.com)
- Improperly used contact lenses can lead to corneal abrasions, corneal edema, corneal ulcers or eye infections, necessitating medical or surgical treatment, ultimately increasing costs and undermining quality of life. (aoa.org)
- In this short video, Alister Chapman describes how he used the Fujinon MK lenses with the SLR Magic Anamorphot 65 anamorphic 1.33x adaptor, the. (fujifilm.com)
- This short documentary was shot using the Fujinon E Mount MK lenses with the SLR Magic Anamorphot 65 1.33x anamorphic adaptor. (fujifilm.com)
- Signet Armorlite, Inc. manufactures and sells the above eyeglass lenses. (kodak.com)
- Eyeglass lenses are mounted in frames worn on the face, sitting mostly on the ears and nose, so that the lenses are positioned in front of the eyes. (encyclopedia.com)
- A separate contact lens -fitting exam is necessary if the patient wants contact lenses, because an eyeglass prescription is not the same as a contact lens prescription. (encyclopedia.com)
- To be suitable for eyeglass lenses, a material must be transparent, without bubbles, and have a high index of refraction. (encyclopedia.com)
- Glass was the first material to be used for eyeglass lenses, and was used for several hundred years before plastic was introduced. (encyclopedia.com)
- Eyeglasses and contact lenses are devices that correct refractive errors in vision. (encyclopedia.com)
- Cosmetic contact lenses can cause problems if they have not been selected and initially fitted with the help of an optometrist to ensure that they are the correct prescription and to minimize the risk of refractive errors. (news-medical.net)
Glasses and Contact Lenses1
- www.wholesalecontactlists**** There has been much discussion as to the origin of glasses and contact lenses, but they are generally believed to have been known at a period much earlier than that of Salvino degli Armati. (metacafe.com)
- fisheye lens on Wikipedia. (wiktionary.org)
- Soft Contact Lens market is further analyzed by the following sub-segments for US, Japan , Europe , and Rest of the World markets: Spherical Lenses, Toric Lenses, and Multifocals. (prnewswire.com)
- The Verisyse lens, made my Advanced Medical Optics, is racing STAAR Surgical neck and neck for the first FDA approval of a permanent, implantable contact lens. (wired.com)
- The Struman Optics case, the clip, and three phone lenses. (digital-photography-school.com)
- Struman Optics has come up with a set of lenses that consider all aspects of using them along with different phone products. (digital-photography-school.com)
- Unlike many other lenses for mobile phones, the Struman Optics ones have covers for the top two brands - both iPhone and Samsung. (digital-photography-school.com)
- The Struman Optics macro lens is incredible. (digital-photography-school.com)
- Fujifilm/FUJINON presents Rhinestone Blue, the first film shot on PREMISTA large format lenses. (fujifilm.com)
- But eyeglasses or contact lenses, also called corrective lenses, can help most people see more clearly. (kidshealth.org)
- this includes prescribing eyeglasses and contact lenses, but also doing eye surgery for other eye-related problems. (kidshealth.org)
- An optometrist is a licensed professional who specializes in eye exams and in figuring out the right prescriptions for eyeglasses and contact lenses. (kidshealth.org)
- Contact lenses are a convenient and comfortable alternative to eyeglasses for many people. (webmd.com)
- Unlike eyeglasses, contact lenses will not fog up due to changes in temperature, and they will not become smudged or smeared during the day. (walgreens.com)
- In addition, contact lenses fully cover the eye, so that your vision is enhanced no matter which direction you look - a benefit that eyeglasses cannot provide. (walgreens.com)
- Just like prescription eyeglasses, you cannot simply wear just any type of contact lenses if you have a refractive error. (mercola.com)
- If you have autofocus lenses they will work on any pentax digital slr. (ephotozine.com)
- While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. (wikipedia.org)
- A first step is to put a simple convex lens at the pinhole with a focal length equal to the distance to the film plane (assuming the camera will take pictures of distant objects  ). (wikipedia.org)
- For a double convex lens the radius R 1 is positive since it is measured from the front surface and extends right to the center of curvature. (gsu.edu)
- There's a feature on the K20 D where if you install a lens that doesn't have all the digital bells and whistles, a message comes up on the monitor to set the focal lenght of the lens and the Image Stabiliser will work with it. (ephotozine.com)
Index of refract1
- The greater the index of refraction, the thinner the lens can be. (encyclopedia.com)
- Micro Four Thirds 100-300mm Telephoto Zoom Lens / 200-600mm (35mm camera equiv. (panasonic.com)
- The Tair 3 is a 300mm f/4.5 telephoto lens. (wikipedia.org)
- The lens enjoys a reputation of having excellent image quality The Tair 33 is a 300mm f/4.5 telephoto lens for Kiev 88 (V Mount, Tair-33V) and Pentacon Six or Kiev 60 system (P6 Mount, Tair-33B). (wikipedia.org)
- The size of the contact lens market is likely to grow due to the increasing occurrence of eye-related conditions such as astigmatism , hyperopia and myopia . (wikipedia.org)
- Color lenses change the color of the eyes while correcting vision, while toric lenses are made for people with an eye condition called astigmatism, which affects the way the eye focuses. (walgreens.com)
- Are Contact Lenses Safe for Astigmatism? (mercola.com)
- They work because their uniform front surface acts as the primary refracting surface of the eye, therefore correcting astigmatism without the control rotation mechanism of toric lenses. (mercola.com)
- The problem with relying on contact lenses for astigmatism or any refractive error is that they can put you at risk of infection. (mercola.com)
- Lens replacement surgery also can correct myopia (nearsightedness), but generally it is not recommended when LASIK, PRK or phakic IOLs are available. (allaboutvision.com)
- Children can independently wear and care for these contact lenses in the age range of nearsightedness, starting about age 7 and beyond," Walline said. (webmd.com)
Contact lens wear6
- The best way to protect your eyes from potential complications is to talk to your eye doctor about decorative contacts and learn about healthy contact lens wear and care habits. (cdc.gov)
- Download sample Halloween-themed social media messages to learn more about healthy contact lens wear and care. (cdc.gov)
- Order or download posters to promote healthy contact lens wear and care habits. (cdc.gov)
- Contact Lens Health Week aims to increase public awareness and promote healthy contact lens wear and care. (cdc.gov)
- CDC is sharing the stories of three people- Whitney , Te' , and Ryan -who suffered from serious eye infections caused by improper contact lens wear and care. (cdc.gov)
- Hygiene is the most critical aspect of successful long-term contact lens wear. (aoa.org)
Proper contact lens1
- Contact an AOA-member doctor of optometry with questions about proper contact lens use and for any other eye health concerns. (aoa.org)
Decorative contact lenses7
- Some decorative contact lenses can turn your Halloween into a nightmare. (cdc.gov)
- Educate yourself and others about the dangers of using decorative contact lenses without a prescription. (cdc.gov)
- Decorative contact lenses bought from costume shops, online stores, beauty salons, convenience stores, flea markets, or any place where a prescription is not required will not be properly fitted to your eyes. (cdc.gov)
- The report says the demand for decorative contact lenses continues to increase, particularly among teenage girls and young women, with consumers spending approximately $180 million on them so far. (emory.edu)
- Because of the growing market, the report states: 'American young people remain at risk as a major target of the unauthorized sale of decorative contact lenses. (emory.edu)
- Having trendy decorative contact lenses is not worth losing your sight. (emory.edu)
- Encounter problems associated with decorative contact lenses? (aoa.org)
- Understand which camera lenses to use and when. (adobe.com)
- Camera bodies are often sold in combination with a lens. (adobe.com)
- Photographers who know what they want can purchase a camera body on its own and then choose their desired lens. (adobe.com)
- Common types of camera lenses. (adobe.com)
- A camera lens (also known as photographic lens or photographic objective ) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically. (wikipedia.org)
- There is no major difference in principle between a lens used for a still camera , a video camera , a telescope , a microscope , or other apparatus, but the detailed design and construction are different. (wikipedia.org)
- If one were inside the camera, one would see the lens acting as a projector . (wikipedia.org)
- A camera lens may be made from a number of elements: from one, as in the Box Brownie 's meniscus lens, to over 20 in the more complex zooms. (wikipedia.org)
- Fingertip control of zoom speed via the zoom lever on the lens barrel or the zoom ring makes it possible to zoom smoothly while maintaining a sure, steady grip on the camera. (sony.com)
- Micro Four Thirds 50-200mm Telephoto Zoom Lens / 100-400mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 8-18mm Wide Zoom Lens / 16-36mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 12-60mm Standard Zoom Lens / 24-120mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 35-100mm Telephoto Zoom Lens / 70-200mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 12-35mm Standard Zoom Lens / 24-70mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 45-200mm Telephoto Zoom Lens / 90-400mm (35mm camera equiv. (panasonic.com)
- Micro Four Thirds 42.5mm Fixed Focal Length Lens / 85mm (35mm camera equiv. (panasonic.com)
- However, it's rumored that Sony will be releasing a camera lens attachment with the same specs as the RX100 II that was recently unveiled . (slashgear.com)
- Here as we saw very, very briefly earlier this week , we've gotten another look at a key accessory for this machine - a camera grip that makes the machine much more like the big-handling machines its amalgamation of lenses and processing abilities suggests. (slashgear.com)
- There are a handful of camera lenses that you can get for the iPhone, which allow you to take a number of unique photos using a fisheye effect or better macro focus. (slashgear.com)
- This camera will work with a fabulous 20x Genuine Canon HD Video Lens and the ability to record straight to MP4. (slashgear.com)
- Learn everything you want about Camera Lenses with the wikiHow Camera Lenses Category. (wikihow.com)
- This video explains all the benefits of MK lenses with Blackmagic Pocket Cinema Camera 4K. (fujifilm.com)
- It's like a miscommunication between camera and lens," says photographer Jason Weingart. (adobe.com)
- When you first buy a lens, it should function predictably with your camera body and your autofocus system should work well. (adobe.com)
- But for some, this may occur about every six months to two years for each camera and lens combination. (adobe.com)
- No, lens calibration is not needed with a mirrorless camera and lens. (adobe.com)
- My lenses are high quality and I wish to use them on any camera I purchase. (ephotozine.com)
- I'm willing to invest in lenses, but my experience has been that 70-80% of the shots I take are created pretty quickly: grab the camera, adjust the zoom, and shoot. (cambridgeincolour.com)
- I now have a Canon 500D, and a 17-55 2.8 IS USM lens, and it's pretty much always on the camera. (cambridgeincolour.com)
- I can fit my camera, a second lens, and a bridge camera in one bag. (cambridgeincolour.com)
- Having two camera bodies will cut down on the need of changing out lenses, but you know what. (cambridgeincolour.com)
- For travel and documentary work, I only carry 2-3 lenses (on average two, usually a fast prime like 35/50 2/1.4, a mid range zoom, and/or telephoto zoom) and only one camera on me. (cambridgeincolour.com)
- A standard 50 mm camera lens doesn't significantly magnify or shrink the image, making it ideal for shooting objects that aren't especially close or far away. (howstuffworks.com)
- A camera lens is actually several lenses combined into one unit. (howstuffworks.com)
- As yet there are no prices available for the camera, lenses or accessories. (techradar.com)
- Some are better than others with most requiring a magnetic ring to attach them to your phone, over the camera lens. (digital-photography-school.com)
- Some have good lenses, but the rings don't work, while others are designed for a particular camera and aren't good on other models. (digital-photography-school.com)
- The phone covers have a section where the camera is that allows you to screw in the lens so it is aligned perfectly with the camera. (digital-photography-school.com)
- The second is a telephoto lens that also has a holder for your phone and small tripod that you can use to help you steady the camera. (digital-photography-school.com)
- We ll safely remove this grime while protecting the most important and sensitive components of your camera and lens. (nikonusa.com)
- Nikon s remarkable system architecture allows for performance upgrades and enhancements through camera and lens firmware updates. (nikonusa.com)
- Expand Collapse My camera or lens seems fine. (nikonusa.com)
- Google filed a patent for a camera-containing contact lens. (popsci.com)
- Such lenses are sometimes called progressives or no-line bifocals. (encyclopedia.com)
Disposable contact lenses1
- She reported wearing disposable contact lenses for approximately six months, often sleeping in them. (emory.edu)