Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Vision, Low: Vision considered to be inferior to normal vision as represented by accepted standards of acuity, field of vision, or motility. Low vision generally refers to visual disorders that are caused by diseases that cannot be corrected by refraction (e.g., MACULAR DEGENERATION; RETINITIS PIGMENTOSA; DIABETIC RETINOPATHY, etc.).Vision Disorders: 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).Vision Tests: A series of tests used to assess various functions of the eyes.Color Vision Defects: Defects of color vision are mainly hereditary traits but can be secondary to acquired or developmental abnormalities in the CONES (RETINA). Severity of hereditary defects of color vision depends on the degree of mutation of the ROD OPSINS genes (on X CHROMOSOME and CHROMOSOME 3) that code the photopigments for red, green and blue.Vision, Binocular: The blending of separate images seen by each eye into one composite image.Visual Acuity: 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.Night Vision: Function of the human eye that is used in dim illumination (scotopic intensities) or at nighttime. Scotopic vision is performed by RETINAL ROD PHOTORECEPTORS with high sensitivity to light and peak absorption wavelength at 507 nm near the blue end of the spectrum.Vision, Monocular: Images seen by one eye.Blindness: The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.Color Perception Tests: Type of vision test used to determine COLOR VISION DEFECTS.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Contrast Sensitivity: The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate visual acuity and to detect eye disease.Visually Impaired Persons: Persons with loss of vision such that there is an impact on activities of daily living.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Eyeglasses: A pair of ophthalmic lenses in a frame or mounting which is supported by the nose and ears. The purpose is to aid or improve vision. It does not include goggles or nonprescription sun glasses for which EYE PROTECTIVE DEVICES is available.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Sensory Aids: Devices that help people with impaired sensory responses.Vision Disparity: The difference between two images on the retina when looking at a visual stimulus. This occurs since the two retinas do not have the same view of the stimulus because of the location of our eyes. Thus the left eye does not get exactly the same view as the right eye.Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Amblyopia: A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Refractive Errors: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.Mesopic Vision: The function of the eye that is used in the intermediate level of illumination (mesopic intensities) where both the RETINAL ROD PHOTORECEPTORS and the RETINAL CONE PHOTORECEPTORS are active in processing light input simultaneously.Fovea Centralis: An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)Eye Diseases: Diseases affecting the eye.Opsins: Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.Strabismus: Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)Lighting: The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.Depth Perception: Perception of three-dimensionality.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Retina: 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.Ophthalmology: A surgical specialty concerned with the structure and function of the eye and the medical and surgical treatment of its defects and diseases.Macular Degeneration: Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.Retinal Pigments: Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.Cataract: Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)Visual Pathways: Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.Space Perception: The awareness of the spatial properties of objects; includes physical space.Sensory Deprivation: The absence or restriction of the usual external sensory stimuli to which the individual responds.Form Perception: The sensory discrimination of a pattern shape or outline.Electroretinography: Recording of electric potentials in the retina after stimulation by light.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Scotoma: A localized defect in the visual field bordered by an area of normal vision. This occurs with a variety of EYE DISEASES (e.g., RETINAL DISEASES and GLAUCOMA); OPTIC NERVE DISEASES, and other conditions.Presbyopia: The normal decreasing elasticity of the crystalline lens that leads to loss of accommodation.Orientation: Awareness of oneself in relation to time, place and person.Discrimination (Psychology): Differential response to different stimuli.Adaptation, Ocular: The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)Motion Perception: The real or apparent movement of objects through the visual field.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Vision, Entoptic: Visual sensation derived from sensory stimulation by objects or shadows inside the eye itself, such as floating vitreous fibers, tissues, or blood.Fixation, Ocular: The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.Glare: Relatively bright light, or the dazzling sensation of relatively bright light, which produces unpleasantness or discomfort, or which interferes with optimal VISION, OCULAR. (Cline et al., Dictionary of Visual Science, 4th ed)Eye Movements: Voluntary or reflex-controlled movements of the eye.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Cataract Extraction: The removal of a cataractous CRYSTALLINE LENS from the eye.ReadingRetinoscopy: An objective determination of the refractive state of the eye (NEARSIGHTEDNESS; FARSIGHTEDNESS; ASTIGMATISM). By using a RETINOSCOPE, the amount of correction and the power of lens needed can be determined.Myopia: 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.Optometry: The professional practice of primary eye and vision care that includes the measurement of visual refractive power and the correction of visual defects with lenses or glasses.Lenses: Pieces of glass or other transparent materials used for magnification or increased visual acuity.Blindness, Cortical: Total loss of vision in all or part of the visual field due to bilateral OCCIPITAL LOBE (i.e., VISUAL CORTEX) damage or dysfunction. Anton syndrome is characterized by the psychic denial of true, organic cortical blindness. (Adams et al., Principles of Neurology, 6th ed, p460)Refraction, Ocular: Refraction of LIGHT effected by the media of the EYE.Retinal DiseasesColor: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Retinal Rod Photoreceptor Cells: Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.Flicker Fusion: The point or frequency at which all flicker of an intermittent light stimulus disappears.Photoreceptor Cells, Vertebrate: Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.Dark Adaptation: Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Fluorescein Angiography: Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.Perceptual Masking: The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.Retinitis Pigmentosa: Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.Cone Opsins: Photosensitive proteins expressed in the CONE PHOTORECEPTOR CELLS. They are the protein components of cone photopigments. Cone opsins are classified by their peak absorption wavelengths.Touch: Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.Visual Prosthesis: Artificial device such as an externally-worn camera attached to a stimulator on the RETINA, OPTIC NERVE, or VISUAL CORTEX, intended to restore or amplify vision.Night Blindness: Failure or imperfection of vision at night or in dim light, with good vision only on bright days. (Dorland, 27th ed)Evoked Potentials, Visual: The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.Eye Injuries: Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.Phosphenes: A subjective visual sensation with the eyes closed and in the absence of light. Phosphenes can be spontaneous, or induced by chemical, electrical, or mechanical (pressure) stimuli which cause the visual field to light up without optical inputs.Size Perception: The sensory interpretation of the dimensions of objects.Glaucoma: An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)Fundus Oculi: The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)Optic Neuritis: Inflammation of the optic nerve. Commonly associated conditions include autoimmune disorders such as MULTIPLE SCLEROSIS, infections, and granulomatous diseases. Clinical features include retro-orbital pain that is aggravated by eye movement, loss of color vision, and contrast sensitivity that may progress to severe visual loss, an afferent pupillary defect (Marcus-Gunn pupil), and in some instances optic disc hyperemia and swelling. Inflammation may occur in the portion of the nerve within the globe (neuropapillitis or anterior optic neuritis) or the portion behind the globe (retrobulbar neuritis or posterior optic neuritis).Proprioception: Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.Optical Illusions: An illusion of vision usually affecting spatial relations.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Retinal Degeneration: A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)Convergence, Ocular: The turning inward of the lines of sight toward each other.Illusions: The misinterpretation of a real external, sensory experience.Distance Perception: The act of knowing or the recognition of a distance by recollective thought, or by means of a sensory process which is under the influence of set and of prior experience.Diabetic Retinopathy: Disease of the RETINA as a complication of DIABETES MELLITUS. It is characterized by the progressive microvascular complications, such as ANEURYSM, interretinal EDEMA, and intraocular PATHOLOGIC NEOVASCULARIZATION.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Microspectrophotometry: Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.Accommodation, Ocular: 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)Contact Lenses: Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)Retinal Detachment: Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Afterimage: Continuation of visual impression after cessation of stimuli causing the original image.Photoreceptor Cells: Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.Orthoptics: The study and treatment of defects in binocular vision resulting from defects in the optic musculature or of faulty visual habits. It involves a technique of eye exercises designed to correct the visual axes of eyes not properly coordinated for binocular vision.Photoreceptor Cells, Invertebrate: Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.Visual Field Tests: Method of measuring and mapping the scope of vision, from central to peripheral of each eye.Hemianopsia: Partial or complete loss of vision in one half of the visual field(s) of one or both eyes. Subtypes include altitudinal hemianopsia, characterized by a visual defect above or below the horizontal meridian of the visual field. Homonymous hemianopsia refers to a visual defect that affects both eyes equally, and occurs either to the left or right of the midline of the visual field. Binasal hemianopsia consists of loss of vision in the nasal hemifields of both eyes. Bitemporal hemianopsia is the bilateral loss of vision in the temporal fields. Quadrantanopsia refers to loss of vision in one quarter of the visual field in one or both eyes.Macula Lutea: An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)Nystagmus, Optokinetic: Normal nystagmus produced by looking at objects moving across the field of vision.Asthenopia: Term generally used to describe complaints related to refractive error, ocular muscle imbalance, including pain or aching around the eyes, burning and itchiness of the eyelids, ocular fatigue, and headaches.Saccades: An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.Models, Psychological: Theoretical representations that simulate psychological processes and/or social processes. These include the use of mathematical equations, computers, and other electronic equipment.Eye ProteinsEye Injuries, Penetrating: Deeply perforating or puncturing type intraocular injuries.Nystagmus, Pathologic: Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)Time Factors: Elements of limited time intervals, contributing to particular results or situations.cis-trans-Isomerases: Enzymes that catalyze the rearrangement of geometry about double bonds. EC 5.2.Optic Atrophy: Atrophy of the optic disk which may be congenital or acquired. This condition indicates a deficiency in the number of nerve fibers which arise in the RETINA and converge to form the OPTIC DISK; OPTIC NERVE; OPTIC CHIASM; and optic tracts. GLAUCOMA; ISCHEMIA; inflammation, a chronic elevation of intracranial pressure, toxins, optic nerve compression, and inherited conditions (see OPTIC ATROPHIES, HEREDITARY) are relatively common causes of this condition.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Pupil: The aperture in the iris through which light passes.Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Optics and Photonics: A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.Corneal Diseases: Diseases of the cornea.Dominance, Ocular: The functional superiority and preferential use of one eye over the other. The term is usually applied to superiority in sighting (VISUAL PERCEPTION) or motor task but not difference in VISUAL ACUITY or dysfunction of one of the eyes. Ocular dominance can be modified by visual input and NEUROTROPHIC FACTORS.Hearing Disorders: Conditions that impair the transmission of auditory impulses and information from the level of the ear to the temporal cortices, including the sensorineural pathways.PrintingAdaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Tomography, Optical Coherence: An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.Lens Implantation, Intraocular: Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.Rhodopsin: A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.Anisometropia: A condition of an inequality of refractive power of the two eyes.Astigmatism: 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)Retinal Ganglion Cells: Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.Diplopia: A visual symptom in which a single object is perceived by the visual cortex as two objects rather than one. Disorders associated with this condition include REFRACTIVE ERRORS; STRABISMUS; OCULOMOTOR NERVE DISEASES; TROCHLEAR NERVE DISEASES; ABDUCENS NERVE DISEASES; and diseases of the BRAIN STEM and OCCIPITAL LOBE.Choroidal Neovascularization: A pathological process consisting of the formation of new blood vessels in the CHOROID.Field Dependence-Independence: The ability to respond to segments of the perceptual experience rather than to the whole.Ocular Motility Disorders: Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)Audiovisual Aids: Auditory and visual instructional materials.Photometry: Measurement of the various properties of light.Laser Coagulation: The use of green light-producing LASERS to stop bleeding. The green light is selectively absorbed by HEMOGLOBIN, thus triggering BLOOD COAGULATION.Vitrectomy: Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma.Raptors: BIRDS that hunt and kill other animals, especially higher vertebrates, for food. They include the FALCONIFORMES order, or diurnal birds of prey, comprised of EAGLES, falcons, HAWKS, and others, as well as the STRIGIFORMES order, or nocturnal birds of prey, which includes OWLS.Sickness Impact Profile: A quality-of-life scale developed in the United States in 1972 as a measure of health status or dysfunction generated by a disease. It is a behaviorally based questionnaire for patients and addresses activities such as sleep and rest, mobility, recreation, home management, emotional behavior, social interaction, and the like. It measures the patient's perceived health status and is sensitive enough to detect changes or differences in health status occurring over time or between groups. (From Medical Care, vol.xix, no.8, August 1981, p.787-805)Lenses, Intraocular: Artificial implanted lenses.Refractive Surgical Procedures: Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Light Coagulation: The coagulation of tissue by an intense beam of light, including laser (LASER COAGULATION). In the eye it is used in the treatment of retinal detachments, retinal holes, aneurysms, hemorrhages, and malignant and benign neoplasms. (Dictionary of Visual Science, 3d ed)Light Signal Transduction: The conversion of absorbed light energy into molecular signals.Reaction Time: The time from the onset of a stimulus until a response is observed.Automobile Driving: The effect of environmental or physiological factors on the driver and driving ability. Included are driving fatigue, and the effect of drugs, disease, and physical disabilities on driving.Darkness: The absence of light.Hyperopia: 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)Corneal Opacity: Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.Differential Threshold: The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold.Leber Congenital Amaurosis: A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.Perceptual Disorders: Cognitive disorders characterized by an impaired ability to perceive the nature of objects or concepts through use of the sense organs. These include spatial neglect syndromes, where an individual does not attend to visual, auditory, or sensory stimuli presented from one side of the body.Cornea: 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)Cebidae: A family of New World monkeys in the infraorder PLATYRRHINI, consisting of nine subfamilies: ALOUATTINAE; AOTINAE; Atelinae; Callicebinae; CALLIMICONINAE; CALLITRICHINAE; CEBINAE; Pithecinae; and SAIMIRINAE. They inhabit the forests of South and Central America, comprising the largest family of South American monkeys.Optic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.Pseudophakia: Presence of an intraocular lens after cataract extraction.Aphakia: Absence of crystalline lens totally or partially from field of vision, from any cause except after cataract extraction. Aphakia is mainly congenital or as result of LENS DISLOCATION AND SUBLUXATION.Retinaldehyde: A carotenoid constituent of visual pigments. It is the oxidized form of retinol which functions as the active component of the visual cycle. It is bound to the protein opsin forming the complex rhodopsin. When stimulated by visible light, the retinal component of the rhodopsin complex undergoes isomerization at the 11-position of the double bond to the cis-form; this is reversed in "dark" reactions to return to the native trans-configuration.Eye Enucleation: The surgical removal of the eyeball leaving the eye muscles and remaining orbital contents intact.Macular Edema: Fluid accumulation in the outer layer of the MACULA LUTEA that results from intraocular or systemic insults. It may develop in a diffuse pattern where the macula appears thickened or it may acquire the characteristic petaloid appearance referred to as cystoid macular edema. Although macular edema may be associated with various underlying conditions, it is most commonly seen following intraocular surgery, venous occlusive disease, DIABETIC RETINOPATHY, and posterior segment inflammatory disease. (From Survey of Ophthalmology 2004; 49(5) 470-90)Esotropia: A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.Papilledema: Swelling of the OPTIC DISK, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause OPTIC ATROPHY and visual loss. (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p175)Vitreous Body: The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.Retinal Artery Occlusion: Sudden ISCHEMIA in the RETINA due to blocked blood flow through the CENTRAL RETINAL ARTERY or its branches leading to sudden complete or partial loss of vision, respectively, in the eye.Ophthalmoscopy: Examination of the interior of the eye with an ophthalmoscope.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Retinal Hemorrhage: Bleeding from the vessels of the retina.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Parrots: BIRDS of the large family Psittacidae, widely distributed in tropical regions and having a distinctive stout, curved hooked bill. The family includes LOVEBIRDS; AMAZON PARROTS; conures; PARAKEETS; and many other kinds of parrots.Activities of Daily Living: The performance of the basic activities of self care, such as dressing, ambulation, or eating.Eye Diseases, Hereditary: Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Electrooculography: Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.Postural Balance: A POSTURE in which an ideal body mass distribution is achieved. Postural balance provides the body carriage stability and conditions for normal functions in stationary position or in movement, such as sitting, standing, or walking.Intravitreal Injections: The administration of substances into the VITREOUS BODY of the eye with a hypodermic syringe.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Optic Nerve Diseases: Conditions which produce injury or dysfunction of the second cranial or optic nerve, which is generally considered a component of the central nervous system. Damage to optic nerve fibers may occur at or near their origin in the retina, at the optic disk, or in the nerve, optic chiasm, optic tract, or lateral geniculate nuclei. Clinical manifestations may include decreased visual acuity and contrast sensitivity, impaired color vision, and an afferent pupillary defect.Signal Detection, Psychological: Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)Eye Protective Devices: Personal devices for protection of the eyes from impact, flying objects, glare, liquids, or injurious radiation.National Eye Institute (U.S.): Component of the NATIONAL INSTITUTES OF HEALTH. It conducts and supports research on the causes, diagnosis, and treatment of diseases of the eye and visual system. It was originally part of the National Institute of Neurological Diseases and Blindness. The National Eye Institute was established in 1968.Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Photorefractive Keratectomy: A type of refractive surgery of the CORNEA to correct MYOPIA and ASTIGMATISM. An EXCIMER LASER is used directly on the surface of the EYE to remove some of the CORNEAL EPITHELIUM thus reshaping the anterior curvature of the cornea.Touch Perception: The process by which the nature and meaning of tactile stimuli are recognized and interpreted by the brain, such as realizing the characteristics or name of an object being touched.Choroid Neoplasms: Tumors of the choroid; most common intraocular tumors are malignant melanomas of the choroid. These usually occur after puberty and increase in incidence with advancing age. Most malignant melanomas of the uveal tract develop from benign melanomas (nevi).Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Endophthalmitis: Suppurative inflammation of the tissues of the internal structures of the eye frequently associated with an infection.Optic Atrophy, Hereditary, Leber: A maternally linked genetic disorder that presents in mid-life as acute or subacute central vision loss leading to central scotoma and blindness. The disease has been associated with missense mutations in the mtDNA, in genes for Complex I, III, and IV polypeptides, that can act autonomously or in association with each other to cause the disease. (from Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/Omim/, MIM#535000 (April 17, 2001))Psychometrics: Assessment of psychological variables by the application of mathematical procedures.Optic Chiasm: The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.Feedback, Sensory: A mechanism of communicating one's own sensory system information about a task, movement or skill.IndiaPupil Disorders: Conditions which affect the structure or function of the pupil of the eye, including disorders of innervation to the pupillary constrictor or dilator muscles, and disorders of pupillary reflexes.Orbital Diseases: Diseases of the bony orbit and contents except the eyeball.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Optic Lobe, Nonmammalian: In invertebrate zoology, a lateral lobe of the FOREBRAIN in certain ARTHROPODS. In vertebrate zoology, either of the corpora bigemina of non-mammalian VERTEBRATES. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1329)

*  Natural Vision Improvement Tips | Complete Eye Care

Since eyes are the most delicate and the most important sensory organs of the human body, we need to be extra careful. Here are some simple tips for a healthy eye that improves the natural vision.. Natural Vision Improvement Tips:. 1. Always take medication on the advice of a medical practitioner and never take medication off the shelf as advised by pharmacists.. 2. Weak eye sight in children should not be ignored and prescribed spectacles should be worn; overlooking this can lead to Amblyopia (Visual impairment without apparent organic pathology ) / Lazy Eye and irreversible loss to vision. 3. Contact lens users should maintain strict hygiene. They should never overuse and should discard their old pair of contacts as prescribed by the manufacturer.. 4. Daily diet should contain fresh fruits and vegetables to ensure healthy eyesight life long.. 5. The recent trend of using anti oxidants for prevention of age related diseases is showing encouraging results ...
complete-eyecare.blogspot.com/2008/11/natural-vision-improvement-tips.html

*  Diabetes and Blurry Vision: What You Need to Know

Blurry vision can be one of the first warning signs of diabetes, but there are also other things that can cause changes to your vision.
healthline.com/health/diabetes/blurry-vision

*  Health Vision Screening: Enter/Edit Data - Illuminate Education

The Health Screening Vision widget shows all information relating to vision screenings. It displays this information by screening date,...
https://support.illuminateed.com/hc/en-us/articles/115000054953-Health-Vision-Screening-Enter-Edit-Data

*  Donate Now | The Low vision Center

This page is for donating on-line. If you prefer to mail us a check, please see our Donations page.. You can donate on-line to the Low Vision Center through either the PayPal Giving Fund or through Network For Good. Please be aware that neither the PayPal Giving Fund nor Network For Good is a part of the Low Vision Center. They are not subject to the LVC web site policies. Note that Network For Good lists the Low Vision Center under our former name, Low Vision Information Center. Your donation will usually not reach the Low Vision Center until late in the month after the month in which you made it. Please be patient if we seem tardy in acknowledging your generosity. If you elect not to divulge your contact information to LVC, we won't be able to thank you for your donation, but in any case you will receive a receipt for your tax records from PayPal Giving Fund or from Network For Good. Select this link to continue to PayPal ...
lowvisioninfo.org/givenow.htm

*  The Link Agency Launches Website for Low Vision Patients, Caregivers of The International Academy of Low Vision S... ...

Health,Barrington RI (PRWEB) August 31 2013 The Link Agency is pleased to announce the launch of a standalone website LowVisionEyeDoctors.com dedicated to educating consumers about low vision and low vision solutions. The site was created for client The International Ac,The,Link,Agency,Launches,Website,for,Low,Vision,Patients,,Caregivers,of,The,International,Academy,of,Low,Vision,Specialists,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
bio-medicine.org/medicine-news-1/The-Link-Agency-Launches-Website-for-Low-Vision-Patients--Caregivers-of-The-International-Academy-of-Low-Vision-Specialists-115283-1/

*  Closed Circuit Television | The Low Vision Center

Video Magnifiers -- These battery-powered devices combine the camera, light source, and small video screen into a single handheld unit. Even devices not specifically designed as low vision aids can be helpful. A digital camera or a cell phone or tablet computer with a built-in camera can sometimes provide enough magnification for certain tasks. The same is true of a computer connected to a camera or document scanner. Apps are available for some smart phones and most computers to allow them to convert text to speech. Remember, you needn't limit your toolbox to only one or two tools! Legally blind people of limited means may be able to get financial assistance for the purchase of a CCTV or other assistive device from the Assistive Technology Fund operated by the Association of Blind Citizens. The Low Vision Center accepts donations of used CCTV systems and sells the donated units to help finance its operations. Follow this link to a list of used CCTV systems currently ...
lowvisioninfo.org/hightech.htm

*  Low Vision Aids

We can provide a wide variety of magnifiers to help if you struggle with low vision, or if you just need a boost for reading. From wallet sized magnifiers with a built-in light, to freestanding magnifiers designed for writing and crosswords and wearable products to help with television watching.. A few of the products we carry are shown below, click on the image for more details. Come into either practice to see the full range.. ...
airedaleopticians.co.uk/our-products/low-vision-aids/

*  Strabismus

Experienced optometrist providing eye care services including prescription eye examinations, diagnosis, treatment, and management of eye disorders such as glaucoma and cataracts, laser surgery and LASIK co-management. Comprehensive optical goods as designer frame eyeglasses, sunglasses and contact lenses. Also provide low vision rehabilitation and vision therapy.
chicago-eyes.com/Content/EyeConditions/strabismus2.aspx

*  synergeyes

Experienced optometrist providing eye care services including prescription eye examinations, diagnosis, treatment, and management of eye disorders such as glaucoma and cataracts, laser surgery and LASIK co-management. Comprehensive optical goods as designer frame eyeglasses, sunglasses and contact lenses. Also provide low vision rehabilitation and vision therapy.
chicago-eyes.com/Content/contactlenses/synergeyes/synergeyes.aspx

*  Living with Low Vision | The Low Vision Center

Overcoming Macular Degeneration: Guide to Seeing Beyond the Clouds by Yale Solomon, M.D>. This book was originally published in 2000, with a revised edition released in 2009. While its details on the current state of research and treatment for age-related macular degeneration might not be up to the minute, it still provides a good broad overview for those affected by the condition. The book is available as a Talking Book (DB73559).. ...
lowvisioninfo.org/living.htm

*  Low Vision Reader - MAGIC Screen Magnification Software

MAGic is a screen magnification and screen reading solution for low vision computer users. MAGic can help you work more efficiently with business applications, documents, email, navigating the Internet, and engaging in social networking. MAGic delivers smooth, crisp letters, even at the highest magnification levels.. ...
iowalowvision.com/magicscreen-magnification.html

*  Low Vision Reader - SARA

SARA is the next-generation self-contained scanning and reading appliance for people who are blind or have low vision. SARA is simple to use, and quickly converts printed text to spoken text. No computer experience is needed. Read your documents without the need for sighted assistance.. ...
iowalowvision.com/sara.html

*  Home | The Low Vision Center

We at LVC have heard of two services that allow a visually impaired individual to connect via video to a sighted person for help with a task that requires visual acuity. We're curious how well these services work. If you've used either of them, please send us an e-mail and tell us what you think of it. Be My Eyes is an app, currently available only for iPhone and iPad, which can set up a video chat session between a blind or visually impaired person wanting help and the first available sighted volunteer willing to give it. Aira is a fee-based service that allows a blind or visually impaired person wearing a head-mounted camera linked to a cell phone to contact a trained agent for assistance with tasks needing visual acuity. Based on the service plan selected, the subscriber is allowed a certain number of minutes of service per month for a fixed monthly fee. ...
lowvisioninfo.org/reverse/index.htm

*  Low Vision Center

We sell donated CCTV systems to help support our free services. The equipment listed below is currently available. Prices are negotiable. Feel free to make your best offer. If you would like to try out any of these devices (whether or not you want to buy it), please call us at 301-951-4444 for a free appointment. Please note: sales of used equipment are final. Be sure to allow enough time to try out the device and verify that it will meet your needs before you buy it. Click on any picture below to see a larger image. ...
lowvisioninfo.org/cctvlist.htm

*  Resources & Links | The Low Vision Center

Contact Us -- LVC has many optical and non-optical aids available for visually impaired people to try. LVC also sells some of the more commonly used aids, such as magnifiers, at competitive prices as a convenience to our clients. Call us at 301-951-4444, or e-mail us at LowVisionCtr@aol.com today. ...
lowvisioninfo.org/resource.htm

*  Links to Other Web Sites | The Low Vision Center

uses the Apple iPhone or iPad to connect blind or visually impaired people to sighted volunteers for help with small tasks requiring eyesight. An app connects the requestor to the volunteer through a video chat session for immediate help. (Since the volunteer will probably be a stranger to you, you should be careful about using this service to read sensitive information such as a bank statement.) ...
lowvisioninfo.org/links.htm

*  Low Vision Resources Center - Latest News

A rigorous clinical trial has found that individuals with diabetic macular edema (DME), whose visual acuity is 20/50 or worse, gained more improvement with Eylea than with Avastin. Aside from that, no significant difference was found among the three anti-VEGF drugs (including Lucentis) in subjects with 20/32 or 20/40 vision at the start of treatment. By two years, 41 percent of participants in ...
lowvision.preventblindness.org/category/latest-news/page/5/

*  Low Vision Reader - ClearView C Flex 24' HD

When we started to develop this video magnifier, we wanted to eliminate all of the difficulties users experienced. After extensive research involving our clients, we came up with a completely new design.. Space saving design The ClearView C Flex is the space saving solution that is perfect for work and school. It takes up less space on your desk, so you have even more room to work.. From basic to powerful options. Whether you prefer simple or advanced options, the ClearView C Flex offers both. Use the simple magnification and contrast buttons, or enjoy powerful advanced functions such as reading lines, additional high contrast colors, writing mode and the advanced menu.. Optional reading table. To help you reading underneath the camera, a useful reading table is optionally available for the ClearView C Flex. The reading table guides movements in a horizontal and a vertical direction ...
iowalowvision.com/flex24-hd.html

*  Low Vision Reader - Optelec MultiView HD 22-inch

Would you like a magnifier that can help you see at any distance? Are you looking for an all-in-one, space saving desktop solution? Then look no further: The MultiView HD is the all-in-one lightweight solution that will save space on your desk and can easily be moved from room to room using the integrated handle ...
iowalowvision.com/multiviewhd-22.html

*  Low Vision Resources Center - Latest News

by Dan Roberts August, 2002 Researchers at the University of Michigan Kellogg Eye Center have discovered a genetic link to a form of macular degeneration. In an article published in August 2002 in Genome ("X-Linked Recessive Atrophic Macular Degeneration from RPGR Mutation," pp. 166-171, doi:10.1006/geno.2002.6815, Radha Ayyagari, et al) the gene RPGR (associated until ...
lowvision.preventblindness.org/category/latest-news/page/25/

*  Low Vision Reader - ClearView C Flex 24 TwinView

From basic to powerful options Whether you prefer simple or advanced options, the ClearView C Flex with TwinView offers both. Use the simple magnification and contrast buttons, or enjoy powerful advanced functions such as reading lines, additional high contrast colors, writing mode and the advanced menu.. Optional reading table To help you reading under the camera, a useful reading table is optionally available. This reading table guides movements in a horizontal and a vertical direction.. ...
iowalowvision.com/cflex24-twinview.html

*  Low Vision

Welcome to The Kenya Society for the Blind Click to listen highlighted text! Welcome to The Kenya Society for the Blind Powered By GSpeech ...
ksblind.org/index.php/resources/resource-centre/low-vision

*  LVI offer solutions for visually impaired people | LVI Low Vision International

LVI is one of the world´s leading manufacturers of equipment for visually impaired people. Our head office is located in Växjö, Sweden. Through our subsidiaries and distributors, we are also well represented worldwide.
lvi.se/en

*  Low Vision Resources Center - Latest News

Stem Cells (STEM) has announced the first patient to receive a high dose of one million purified human neural stem cells (HuCNS-SC®) in their Phase 1/2 clinical trial. This followed an independent review by the Data Safety Monitoring Committee, which found no safety issues with proceeding to the high dose. The 16-patient trial is designed to evaluate ...
lowvision.preventblindness.org/category/latest-news/page/20/

*  Gait disorder and Visual problems - Symptom Checker - check medical symptoms at RightDiagnosis

List of causes of Gait disorder and Visual problems, alternative diagnoses, rare causes, misdiagnoses, patient stories, and much more.
wrongdiagnosis.com/cosymptoms/gait-disorders/visual-problems.htm

*  Diagnosis of visual impairment

If visual problems are suspected an ophthalmologist usually examines the eyes. An ophthalmologists specializes in diagnosing, and treating eyes and their diseases.
https://news-medical.net/health/Diagnosis-of-visual-impairment.aspx

*  Vision - Health Concerns - Nutrition Express

Low prices on Vision and Eye Health! Protect your eyesight*. Taking a proactive approach toward slowing the compounding effects of age-related vision changes is the best way to ensure a keen sense of sight. A combination of vision-specific minerals, botanicals and potent antioxidants, all researched to protect and support eye tissue, can be effective in promoting eye health. Lutein is a naturally occurring antioxidant carotenoid found in large concentrations in the eye.
https://nutritionexpress.com/health concerns/vision/lindberg bilberry extract 80 mg 90 capsules.aspx

*  Procedures

A video of a dog named Duffy who underwent surgery to regain his eyesight went viral. Here is a little behind the scenes content on how a procedure like this was done directly from the doctor who performed it, Dr. Brady Beale ...
pethealthnetwork.com/tags/procedures

*  Holiday tip: mini-size it! | The Portion Teller

Holiday tip: mini-size it! Mini-size it! A great way-perhaps the best way-to cut calories is to trim your portion sizes. Especially of foods that are high in calories. That would include many treats you would find at holiday parties and events ...
portionteller.com/holiday-tip-mini-size-it/

*  Smile, you're on candid computer - Computerworld

An elderly man squints at an automated teller machine (ATM) screen and the font size doubles almost instantly. A woman at a shopping center kiosk s...
https://computerworld.com.au/article/35984/smile_re_candid_computer/

*  Color Blindness, Red-Green, Partial | Hereditary Ocular Diseases

Human color vision is trichromatic and requires the normal function of three classes of cones responding to wavelengths of approximately 420nm (blue cones), 530 nm (green cones), and 560 nm (red cones). Dichromatic color vision discussed here is based on responses of red and green cones whose pigments are generated from contiguous gene regions on the X chromosome encoding OPN1MW (green pigment), and OPN1LW (red pigment).. The degree of color deficiency is variable and some males are so mildly affected that they are unaware of any defect until tested. The human eye is capable of seeing about a million colors which is made possible in part by the wide range of comparative signal outputs from the three classes of cones. In addition, the ratio of red and green cones varies among individuals and these factors collectively influence how each individual interprets the spectrum of wavelengths that enter the eye. The phenotype of red-green color blindness is highly variable. Four ...
disorders.eyes.arizona.edu/disorders/color-blindness-red-green-partial

*  Learn about Vision Issues: Color Blindness

Being color blind probably isn't what you expected. Color blindness rarely results in seeing no color at all, and it is usually not correctable.
eyeglassworld.com/eye-vision-patient-education/vision-issues/color-blindness/

*  Color Blindness Statistics Gender Flashing Vision Lights Blurred Eyes - Eyes Deporteintegra

WebMD provides information about common drug or vitamin interactions for Ocuvite Lutein and Zeaxanthin oral. Color Blindness Statistics Gender Flashing Vision Lights Blurred Eyes levine Shaban Demirel Juanjuan Fan John L. by the kidneys to reduce the risk of forming calcium kidney stones.. For some the next step would be transitioning to a prescription concentration of retinoic acid. Her main symptom seems to be pain behind her left eye. also includes the mean difference in spherical equivalent refraction between eyes.. Your nose is still bleeding even after 20 full minutes of direct pressure. Gonococcal conjunctivitis information including symptoms diagnosis misdiagnosis treatment causes patient stories videos forums. Wilson's disease - the Kayser-Fleischer ring occurs when copper is.. Santry swift explained keelboatmen selling their dinadan and millington Hovering angel navvy work having diabetic retinopathy screening. Energy Boost with Ginseng. slight body aches a mild headache a ...
deporteintegra.eu/eaoaeat-eyes/color-blindness-statistics-gender-flashing-vision-lights-blurred-eyes/

*  Conjunctivitis Of Both Eyes Code Vitamin B3 Therapeutic Uses - Eyes Deporteintegra

To develop the clinical practice guideline on the management of AOM the American Academy of Pediatrics (AAP) and American Academy of Family Physicians (AAFP Antara khasiat-khasiat Collagen Delimalicious White ini ialah kuku dan rambut , menguatkan otot sendi , melewatkan penuaan , menghilangkan lingkaran gelap di bawah mata , menutup liang pori terbuka Silalah cuba COLLAGEN DELIMALICIOUS ASTAXANTHIN WHTE minuman kolagen yang Feline systemic hypertension: Workup for a blind cat; Check blood pressure for first 48 hrs. Conjunctivitis Of Both Eyes Code Vitamin B3 Therapeutic Uses atlas Eye specializes in Refractive Surgery Fast Recovery Less Dry Eye. Color Vision Genetics Evolution Simulation 7 - 12th a form of color blindness where for your school and take advantage of the Color of Life Educa- Do Glasses for Color Blindness Work? EnChroma color blindness glasses may not work for much and cause color confusion.. Depending on what is causing the eye discharge additional symptoms may include: ...
deporteintegra.eu/eaoaeat-eyes/conjunctivitis-of-both-eyes-code-vitamin-b3-therapeutic-uses/

*  Human Vision and Color Perception - matetip.com

Table 1. Tritanopia is the absence of blue sensitivity, and functionally produces a blue-yellow defect in color vision. Individuals with this deficiency cannot distinguish blues and yellows, but do register a difference between red and green. The condition is quite rare, and occurs about equally in both sexes. Tritanopes usually do not have as much difficulty in performing everyday tasks as do individuals with either of the red-green variants of dichromacy. Because blue wavelengths occur only at one end of the spectrum, and there is little overlap in sensitivity with the other two cone types, total loss of sensitivity across the spectrum can be quite severe with this condition.. When there is a loss of sensitivity by a cone receptor, but the cones are still functional, resulting color vision deficiencies are considered anomalous trichromacy, and they are categorized in a similar manner to the dichromacy types. Confusion often arises because these conditions are named ...
matetip.com/2011/12/18/human-vision-and-color-perception/

*  Explore... Parenting: Does a Child See What You See?

Does a Child See What You See?. By Arlene Evans. Joey Knight was puzzled. What did his parents mean by color? Green shirt, red shirt, brown shirt, gray shirt. Huh? They all looked pretty much the same to him. He figured his parents were just smarter than he was. Approximately 1:12 males and 1:200 females has some degree of color vision deficiency or colorblindness. Pre-school books, puzzles, games and other toys are colored intensely enough that most children can tell the colors apart, although they may not look the same to the child with CVD as they do to most people. However, two percent of the male population (and a rare female) cannot see red or green at all, and they confuse other colors as well. These children may not catch on easily to pre-school games that are based on color. They may also resist playing with puzzles that rely as much on color as on shape. They may not be as enthralled with crayons as are most children. They"d just as soon draw with a fat pencil. They may not see ...
https://trans4mind.com/explore/parenting/29255.html

*  Manfred's Blog: December 2007

A4: Simply told: the color vision deficiency resides on the X chromosome. This means that if man has the defect X chromosome he is colorblind. If a woman has the defect X chromosome then he is not colorblind because the healthy X chromosome is used. If it is the case that both X chromosomes of a woman are defect then also a woman can be colorblind but as far as I know there are only very few cases on the world. The other thing is that women are the carriers for defect chromosome. This means I (as man who is colorblind) have a daughter and she has a son then the probability that the son is colorblind is very high. My direct sons are not affected ...
manfred-ramoser.blogspot.com/2007/12/

*  Glasses correct boy's color blindness | KVAL

Cayson Irlbeck has been color blind since birth.Then he tried on a pair of special glasses.It was instant, he said. I knew right away something had changed, how bright everything was.
kval.com/news/videos/glasses-correct-boys-color-blindness

*  The Biological Perspective: Nervous System Functioning and Biochemistry

Researchers continue to explore the effects of single gene pairs or other relatively simple genetic etiology on specific behavior disorders. Such research has been facilitated by new genetic methods (cf. Lombroso et al., 1994). Segregation analysis uses statistical procedures to examine the pattern of disorder as well as genetic makeup within a family and compare it to a specific genetic model of inheritance, such as a dominant or recessive gene model. The results allow inferences about the pattern of genetic inheritance for a disorder. Linkage analysis explores whether the pattern in which a specific disorder appears among family members is the same as for genetic markers. The approximate chromosome location is known for the genetic markers. For example, inherited disorders, such as color blindness, that are known to be linked to a particular chromosome have been used as markers. If the behavior disorder and color blindness appear in family members in the same pattern then it can be presumed ...
onno95.blogspot.com/2010/06/biological-perspective-nervous-system.html

*  Color blind Illustrations and Clipart. 1,193 Color blind royalty free illustrations, and drawings available to search from...

1,193 Color blind illustrations and clipart. Affordable Royalty Free Stock Photography. Downloads for just $2.50, with thousands of images added daily. Subscriptions available for just $39.00. Our stock photo image search engine contains royalty free photos, vector clip art images, clipart illustrations.
https://canstockphoto.com/illustration/color-blind.html

*  The Enablist: Are we rejecting Color Blind Civil Services candidates because of an oversight?

Sir this initiative started by you is worth praising. Atleast someone took it.But I would like to inform you that there are many non tech posts like few posts in incometax, all posts in RTO, A and B1 posts in Railways where colorblinds are barred. Also in employment advertisement its clearly mentioned that for xyz post colorblindness is a disqualification. So if these people they are rejected for the post where it was mentioned that colorblindness is not a disqualification, then they can challenge it legally as its in no way acceptable that authorities take colorblindness test and reject candidates. Secondly government sector employs a small fraction of population. The major problem is faced by candidates in private sector too, where MNCs reject candidates based on Color Blindness even if no color identification is required to perform the job. For eg designing software.Because every software like phones user interface, windows , websites etc are all designed by keeping in mind the colorblind ...
theenablist.blogspot.com/2015/06/are-we-rejecting-color-blind-civil.html

*  Learning to see color? - colorblind vision | Ask MetaFilter

I have the standard garden variety red-green color blindness. Confusing colors as a youth happened alot more now, owing to the fact that my brain built 1000s of maps and scenarios about color since then. I still don't much better on the standard number tests, though. I do notice that I can barely discern some of the same ones I had trouble seeing the number in when I was younger when I really try to relax my mind/eyes. There's probably a mechanical (not non-physical) action at work then that allows the retinas to refocus or otherwise make better use of the available cones. Perhaps the first part of my answer (building mind maps) is attributable to perceptual rather than non-physical. Having a large box of Crayolas as a kid was really valuable in this regard. But I still dress in conservative colors for fear of mismatches ...
ask.metafilter.com/83096/Learning-to-see-color

*  Psych Central - Behavioral studies show UV contributes to marsupial color vision

Work reported this week provides new evidence that marsupials, like primates, have functional color vision based on three different types of color photoreceptor cones -- but unlike primates, a component of marsupial color vision includes sensitivity to ultraviolet wavelengths. In the study, researchers employed behavioral tests to show that at least one type of marsupial uses its detection of UV light as part of its ability to discriminate between colors.
https://psychcentral.com/news/archives/2006-03/cp-bss031606.html

*  Vision and Light-Induced Molecular Changes

Now that we have studied the vision process for monochrome vision, we can turn our attention to color vision. Recall that the nerve signals for color vision are generated in the cone cells. Color vision in the cone cells operates by essentially the same process as the monochrome vision in the rod cells. However, whereas the eye only has one type of rod cell, the eye has three different types of cone cells. The differences between the three types of cone cells, as we shall see below, allow us to distinguish colors.. Our color vision is trichromatic, i.e., we perceive color through three fundamental receptors: red-absorbing, green-absorbing, and blue-absorbing cone cells. Each color in the visible spectrum can be made by a mixture of these three primary colors recognized by the three types of cone cells. Each type of cone cell contains a different protein bound to 11-cis-retinal and has its ...
chemistry.wustl.edu/~edudev/LabTutorials/Vision/Vision.html

*  Re: Avian color vision

On Fri, 30 Jun 2006 10:47:05 -0700 Dino Guy Ralph ,dinoguy@sbcglobal.net, writes: , In every copy of the July _Scientific American_ at my local store, , the avian , color vision article has one flawed page that is faded and blurred. , Are all , copies of this article defective, or just the 'Special California , Editions' , of the magazine? Maybe it was meant to be vision test! ;-) ,pb, -- [No .sig today ...
dml.cmnh.org/2006Jun/msg00525.html

*  Sex chromosome shocker: The "female" X a key contributor to sperm production - Healthcanal.com : Healthcanal.com

This surprising finding, reported by Whitehead Institute scientists in a paper published online this week in the journal Nature Genetics, is paired with another unexpected outcome: despite its reputation as the most stable chromosome of the genome, the X has actually been undergoing relatively swift change. Taken together, these results suggest that it's time to reexamine the biological and medical importance of the X chromosome. "We view this as the double life of the X chromosome," says Whitehead Institute Director David Page, whose lab conducted this latest research. "The X is the most famous, most intensely studied chromosome in all of human genetics. And the story of the X has been the story of X-linked recessive diseases, such as color blindness, hemophilia, and Duchenne's muscular dystrophy," Page adds. "But there's another side to the X, a side that is rapidly evolving and seems to be attuned to the reproductive needs of males." Page's lab, best known for its pioneering investigations of ...
https://healthcanal.com/male-reproductive/41073-sex-chromosome-shocker-the-female-x-a-key-contributor-to-sperm-production.html

*  Malcolm's Musings: A Zoologist Looks at Science Fiction: Interplanetary Hybrids

The eyes of a mollusc, such as a giant squid, and those of a vertebrate, such as us, look very similar, and they function just as effectively. However, the rear of the eye is structured quite differently in the two groups. And while we are on the subject of eyesight, we might mention colour vision. The back part of our eye contains cells called cones, with pigments in three different colours: red, green, and blue. We can distinguish a million separate colours by matching the incoming light against the proportion absorbed by each of the pigments. Colour blind humans usually have one of the pigments out of kilter with the others, and less often lack one of the pigments. It would be incredible if an alien had exactly the same pigments as us. But most mammals possess only two pigments. Contrary to what you may have heard, they do not see the world in black and white, but they do lack the red pigment. But most birds, reptiles, and amphibians, not to mention most insects, have four pigments. Some, ...
malcolmsscifi.blogspot.com/2014/08/interplanetary-hybrids.html

*  R Hydrae | aavso.org

Within this context, Zijlstra et al. (2002) propose that there are two currently accepted models used to describe the reduced period seen in R Hya:. Post-thermal-pulse evolution - Within this theory, the thermal pulse is believed to occur when a sufficient amount of helium has accumulated under the hydrogen burning layer. The result of the pulse would be a strong modulation of luminosity, which would peak over a time scale of about 10-100 years followed by a plateau, which would occur at the hydrogen burning luminosity on a shorter timescale. A decline in luminosity would ensue for a few hundred years. When the helium burning halts after about 1,000-10,000 years and the hydrogen layer begins to fuse for the next 10,0000-100,000 years, the star quickly recovers its pre-pulse luminosity. It is thought that the period and mass-loss rate would follow this luminosity evolution. The decline in luminosity would cause a reduction in stellar radius, which in turn, would cause the period to become ...
aavso.org/vsots_rhya

*  TRITANOPIA перевод с английского на русский, translation English to Russian. Англо-Русский научно-технический словарь

мед. тританопия (разновидность дальтонизма неспособность различать фиолетовый, синий и зелёный цвета)
slovar-vocab.com/english-russian/scientific-technical-vocab/tritanopia-4445745.html

*  Comprehensive Exam vs. Binocular Vision Exam

Comprehensive eye exams are VERY important. They measure visual acuity and any prescription needed to improve the acuity. Most people want to see perfectly and often, glasses and contacts are all that is needed to improve their sight. Comprehensive exams also evaluate the health of the front and the back of the eye. The pressure inside the eye is measured to determine the risk of glaucoma. Frequently, eye health issues are found that could point to problems as the person matures, so this information is of extreme importance. In addition, systemic (general body) health problems can be found by changes found inside the eye during the exam.. The binocular vision exam is examining how the two eyes work together. These exams are for many more conditions other than a "lazy eye." The binocular vision exam includes the evaluation of the following skills:. Near focusing skills (accommodation). Eye posture (distance and near). Eye fixation and coordination. Eye movement and tracking ...
https://sightwork.com/2017/08/07/comprehensive-exam-vs-binocular-vision-exam/

*  Binocular Vision and Ocular Motility (VS21203) Course Description

This course presents elements of binocular vision and ocular motility. Binocular vision topics include oculocentric and egocentric localization, binocular correspondence…
neco.edu/course/binocular-vision-and-ocular-motility-vs21203

*  From local constraints to global binocular motion perception - Enlighten: Theses

Humans and many other predators have two eyes that are set a short distance apart so that an extensive region of the world is seen simultaneously by both eyes from slightly different points of view. Although the images of the world are essentially two-dimensional, we vividly see the world as three-dimensional. This is true for static as well as dynamic images. We discuss local constraints for the perception of three-dimensional binocular motion in a geometric-probabilistic framework. It is shown that Bayesian models of binocular 3D motion can explain perceptual bias under uncertainty and predict perceived velocity under ambiguity. The models exploit biologically plausible constraints of local motion and disparity processing in a binocular viewing geometry. Results from psychophysical experiments and an fMRI study support the idea that local constraints of motion and disparity processing are combined late in the visual processing hierarchy to establish perceived 3D motion direction. The methods ...
theses.gla.ac.uk/5218/

*  Binocular Vision: Beyond the Basics (ELC63001) Course Description

This elective course will present a problem solving approach to dealing with complicated binocular dysfunctions. The participants will learn HOW to develop…
neco.edu/course/binocular-vision-beyond-the-basics-elc63001

*  New Research From Psychological Science - Association for Psychological Science

Read about the latest research published in Psychological Science. Seeing in 3-D With Just One Eye: Stereopsis Without Binocular Vision Dhanraj Vishwanath and Paul B. Hibbard Researchers have long thought that stereopsis -- the sense of depth and immersive …
psychologicalscience.org/news/releases/new-research-from-psychological-science-58.html

*  Comparison of visual acuity charts in young adults and patients with diabetic retinopathy. - Nuffield Department of...

PURPOSE: To compare visual acuity (VA) assessed in healthy eyes and eyes with diabetic retinopathy (DR) using three different logMAR charts: the Sloan letter European-wide chart, the tumbling E chart, and the Landolt C chart. METHODS: Measurements on one eye of 40 volunteers (aged 29 ± 4 years) without visual impairment and 31 DR patients (aged 70 ± 9 years) with mild/moderate visual impairment were included. Visual acuity was assessed, with habitual refractive correction, using each of the three charts. Bland-Altman charts were constructed, and 95% limits of agreement were calculated to measure agreement. RESULTS: Mean VA in the group of young adults was -0.05 ± 0.10 (Sloan letter), -0.02 ± 0.13 (tumbling E), and 0.00 ± 0.12 (Landolt C) logMAR. Average VA estimates differed to a statistically significant extent between all charts. Mean VA in the DR group was 0.46 ± 0.25 (Sloan letter), 0.48 ± 0.26 (tumbling E), and 0.59 ± 0.28 (Landolt C). A statistically significant difference was observed for
https://ndorms.ox.ac.uk/publications/552495

*  Unilateral visual impairment and neurodevelopmental performance in preschool children | British Journal of Ophthalmology

Background: Unilateral visual impairment (UVI) as a result of amblyopia or refractive error is common in childhood, but its functional significance remains largely unexplored.. Aim: To investigate the influence of visual acuity and stereoacuity on the performance of preschool children on tasks requiring visuomotor skills and visuospatial ability.. Methods: Children with normal (6/6) visual acuity (VA) in both eyes and children with UVI ranging from 6/9 to 6/60, with no strabismus and normal vision in the fellow eye, were assessed on a neurodevelopmental test battery of visually guided tasks.. Results: 50 children (mean age (SD): 52.4 (5.7) months; median (range) VA: 6/9 (6/6 to 6/60); median (range) stereoacuity: 70 seconds arc (40-absent)) completed the test battery. UVI and stereoacuity correlated moderately (Pearson's r = 0.537, p,0.001) but seven of 28 children with impaired VA had normal stereoacuity (,70 seconds arc) while five of 22 with normal VA had abnormal stereoacuity. ...
bjo.bmj.com/content/90/7/836

*  How to check visual acuity ? - OutHows.info

To determine the visual acuity should be taken close to a book or magazine with a clear font, the size of which shall be not less than 2 mm.It is necessary to place the text at a distance of about 35 cm from the eye.It is best to keep the book at eye level, so as not to have to constantly bend over, changing the angle of vision.Read the text should be alternately closing his eyes.With the right visual acuity you will be well to distinguish between letters, you definitely have an incentive to push the book, and also bring her closer.Refer to a clinic or a special ophthalmic clinic for more detailed examination.Man must see a doctor at least once every 2 years, even if there are no complaints about the vision.It is necessary to prepare for a visit to the doctor.For 24 hours before the test can not drink alcohol and, if possible, different drugs, which have side effects to the eye.The acuteness of his near vision should be checked on a special card, similar to ...
outhows.info/en/pages/1286924

*  Visual Acuity : Knowledge Base DIALux evo

Visual acuity is the ability of the human eye to discriminate between adjacent objects. It depends to a significant degree on the levels of contrast and luminance in the field of vision. Optimum conditions start at around 100 cd/m2 with a contrast difference of over 90%. At average reflectance this corresponds to an illuminance of 1000 lx. In the case of moving objects visual acuity increases slightly, reaching a maximum at angular velocities of 2-3 degrees of angle per second.
evo.support-en.dial.de/support/solutions/articles/9000078541-visual-acuity

*  Relationship between retinal microstructures and visual acuity after cataract surgery in patients with retinitis pigmentosa |...

Results The postoperative BCVAs in logMAR units (Grade 1, 1.04±0.36; Grade 2, 0.33±0.16; Grade 3, 0.08±0.14) and the improvements in the BCVA in logMAR units (Grade 1, 0.22±0.28; Grade 2, 0.53±0.48; Grade 3, 0.54±0.35) were significantly different among Grade 1, 2 and 3 groups (p,0.0001, p=0.0378; respectively). A postoperative BCVA of ,0.2 logMAR units was achieved in 0% in Grade 1, 20% in Grade 2 and 74% in Grade 3 (p,0.0001). There was a significant correlation between the postoperative BCVA and the length of the IS/OS line (r=−0.601 p,0.0001) or the CFT (r=−0.510, p,0.0001).. ...
bjo.bmj.com/content/99/4/508

*  We'll never know if statins are safe while commercial interests come first

What we know about statins comes almost entirely from commercial interests. So what we take for knowledge about their harms and benefits is actually information designed to optimise the drug makers' responsibility…
theconversation.com/well-never-know-if-statins-are-safe-while-commercial-interests-come-first-24608

*  Lab 8: Visual Acuity: Testing Your Peripheral Vision - MAEDA HS Science Fair

When you look at an image, rays of light fly directly into your eye, allowing you to see an image. Vision is caused by a variety of light rays hitting what is called the retina, a thin layer of cells at the back of your eye that processes images. Once the image is processed, it is sent as an electrical signal by your neurons to a special area of your brain called the Occipital lobe, which is responsible for processing mainly vision ...
maedahsbio.weebly.com/lab-8-visual-acuity-testing-your-peripheral-vision.html

*  Understanding the Visual Acuity | Complete Eye Care

If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United ...
complete-eyecare.blogspot.com/2008/08/understanding-visual-acuity.html

*  Visual Acuity

Binocular alignment is evaluated with a cover test. The examiner holds a point light source beneath his or her own eyes and observes the light reflections in the patient's corneas in the near field (40 cm) and at a distance (5 m). The reflections are normally in the center of each pupil. If the corneal reflection is not in the center of the pupil in one eye, then a tropia is present in that eye. Then the examiner covers one eye with a hand or an occluder (Fig. 1.6) and tests whether the.... ...
https://alpfmedical.info/visual-acuity/

*  UrbanMedium Online Store - Visual Acuity Screen Print

Limited edition screen print entitled 'Visual Acuity' - 30 prints per color (red or black), 18x24 hand pulled 80lb stock. Signed by artist,...
urbanmedium.bigcartel.com/product/visual-acuity-screen-print

*  East-West Wellness Medical Center - Visual Acuity

The East-West Wellness Medical Center uses the best of Eastern and Western medicine to create innovative new therapies with profound results.
drtong.com/tag/visual-acuity/

*  How do I convert from diopters to 20/20 vision? | Reference.com

It is impossible to convert 20/20 vision directly into diopters because they are two different measures of sight. However, there is a correlation between the measure of visual acuity (20/20) and the...
https://reference.com/health/convert-diopters-20-20-vision-af78dbce9ea3d3cc

*  Options For Helping Improve Night Vision

Can you see at night as well as you think you should? If the answer is no, just know that you're not alone. Many people feel that their night vision is weaker than it should be, and that can lead to problems. For one thing, it makes driving at night difficult at best, and downright dangerous at worst. If you worry about your night vision while you're driving, then maybe it's time to do something about it. So take a look at some of your options for improving your night vision.. Give Yourself Some Time. If you feel like your night vision is bad, take a look at how you're using it. Do you walk out from your brightly lit apartment to your car on the dimly lit street, hop in, and start driving? If so, then you probably will have some difficulties. You have to give your eyes some time to adjust. It takes nearly half an hour for our eyes to fully adjust to darkness, and that's when you're avoiding bright lights in the meantime.. Protect Your Eyes. ...
eyecare2020.com/blog/2017/04/options-for-helping-improve-night-vision/

*  Night Vision Optics

... Infrared Binoculars and Infrared night vision Monoculars. Bushnell Equinox Z Binocular and Monocular are just a few of our night vision range of optics. High performance night vision optics at low prices. 2 Year warranty included.
https://gardenature.co.uk/shop/watching-wildlife/binoculars-spotting-scopes/night-vision-optics

*  BNVDG Night Vision Binocular - Dual Gain - Night Vision Devices

The NVD Binocular Night Vision Device is a dual tube night vision goggle that offers outstanding depth perception and is now enhanced with Gain Control.
nvdevices.com/products/night-vision/bnvdg-night-vision-binocular/

*  F5050 Night Vision Binocular - Night Vision Devices

The ITT Exelis Night Vision F5050 Night Vision Binocular utilizes aviation standard optics and high resolution Gen 3 F9800 image intensifier tubes.
nvdevices.com/products/night-vision/f5050-night-vision-binocular/

*  Tracker Night Vision Goggle Binocular - from category Optics (JayMaq Outdoor Gear | Where the Outdoors Come Into View)

Buy Tracker Night Vision Goggle Binocular. Optics - Tracker Night Vision Goggle Binocular. Firefield, a world wide leader in the development and distribution of night vision and sporting optics, stay true to their one simple mission; to produce high quali
https://jaymaqoutdoorgear.com/optics-outdoor-gear/Night-Vision-Accessories/tracker-3x42-night-vision-binos-outdoor-gear

*  Night Vision Monoculars - Night Vision Depot

Night Vision Monoculars are the most versatile night vision systems available. They can be hand held, helmet mounted or even weapon mounted.
nvdevices.com/product-category/night-vision/monoculars/

*  BNVD-SG Night Vision Binocular - Single Gain - Night Vision Devices

The Night Vision Devices (NVD) Binocular Night Vision Device with Gain Control (BNVD-SG) has been redesigned to be lighter while increasing performance.
nvdevices.com/products/night-vision/bnvd-sg-night-vision-binocular/

*  ATN NVMNMON410 MO4-1 Night Vision Monocular FREE SHIPPING!

ATN NVMNMON410 MO4-1 Night Vision Monocular The ATN MO4-1 night vision monocular comes with a suite of advanced features to give it an edge over the competition. Equipped with a first-generation intensifier tube and a 3x magnification objective lens, it is ideal for long-distance observation in low-light conditions. The premium multi-coated, all-glass optics maximize light transmission, providing the brightest and clearest image possible. When ambient light levels drop to zero, the infrared illuminator offers continued visibility without giving away your movements like a flashlight. The beam pattern can be adjusted using the user-friendly digital controls, allowing you to adapt it to suit your immediate tactical needs. The scope also features SMART Technology, a proximity-activation system that switches it on when held in a viewing position to preserve battery power and intensifier lifetime.
https://copsplus.com/atn-mo4-1-night-vision-monocular

*  Wholesale Min. Illumination Color 0.01Lux Night Vision Wireless Home Security Systems from China ineSun.com

Wholesale China Min. Illumination Color 0.01Lux Night Vision Wireless Home Security Systems, browse through our selection of Min. Illumination Color 0.01Lux Night Vision Wireless Home Security Systems at ineSun.com!
inesun.com/Wireless-Home-Security-Systems--a657/Min.-Illumination-Color-0.01Lux-41/Night-Vision-16/

*  AN/PVS-15 MIL Spec Night Vision Binocular - Night Vision Devices

The AN/PVS-15 MIL Spec Night Vision Binocular provides greater depth perception which can be critical when performing surveillance and recognition missions.
nvdevices.com/products/night-vision/an-pvs-15-night-vision-binocular/

*  Ultra-Light PVS-14 (UL-14) Night Vision Monocular - Night Vision Devices

The Ultra-Light PVS-14 Night Vision Monocular utilizes light weight optics and a battery housing with digital push buttons instead of heavy analog switches
nvdevices.com/products/night-vision/ultra-light-pvs-14-ul-14-night-vision-monocular/

*  Konus KONUSPY-6 5x Digital Night Vision Monocular 7927 B&H Photo

Buy Konus KONUSPY-6 5x Digital Night Vision Monocular features Digital Image Sensor, Integral Infrared Laser Illuminator. Review Konus NV Monoculars & Multi-Systems, Night Vision Devices
https://bhphotovideo.com/c/product/1221454-REG/konus_7927_konuspy_6_5x_digital_night.html

*  AstroScope Night Vision Adapter 9350-PD-3LPRO 914843 B&H Photo

Buy AstroScope Night Vision Adapter 9350-PD-3LPRO features For Sony PD150/PD170/VX2100, 23mm f/1.2 C-Mount Lens. Review AstroScope Photo/Video Converter Adapters, Night Vision Accessories
https://bhphotovideo.com/c/product/555489-REG/AstroScope_914843_Night_Vision_Adapter_9350_PD_3LPRO.html

*  BMNVDG Night Vision Binocular/Monocular - Night Vision Devices

The BMNVDG is a revolutionary new concept that combines all the best features of a monocular and binocular into one fully functional night vision device.
nvdevices.com/products/night-vision/bmnvdg-night-vision-binocular-monocular/

*  NVD-SFK-14 Night Vision Monocular Kit - Night Vision Devices

Our PVS-14 Night Vision Monocular Special Forces Kit combines those accessories most often required for special operations into one easy to purchase package
nvdevices.com/products/night-vision/nvd-sfk-14-night-vision-monocular-kit/

*  PVS-14 Night Vision Monocular - Night Vision Devices

Starting at $3195, the PVS-14 is the all around best multi functional night vision monocular and is available with Commercial, MIL GRADE or MIL SPEC tubes.
nvdevices.com/products/night-vision/pvs-14-night-vision-monocular/

*  Discount Binoculars Nampa ID - Discount binoculars, Nampa ID night vision binoculars, Nampa ID vision binoculars, Nampa ID ...

Local resource for discount binoculars in Nampa, ID. Includes detailed information on local businesses that provide access to discount binoculars, night vision binoculars, vision binoculars, monoculars, bird watching equipment, and scopes and binoculars, as well as advice and content on binocular reviews, binocular prices, and binocular ratings.
local.birdwatchersdigest.com/Discount_Binoculars_Nampa_ID-p1568015-Nampa_ID.html

*  Night Owl iGEN 20/20 Day/Night Vision Monocular with Image Caputre (3x) Reviews - alaTest.com

Read 10 reviews and find the lowest price for the Night Owl iGEN 20/20 Day/Night Vision Monocular with Image Caputre (3x). Overall, this Binocular is rated 81/100 Very good.
alatest.com/reviews/binocular-reviews/night-owl-igen-image-capture-nachtsichtgerat/po3-63174860,26/

*  Night Owl Cyclops Compact Night Vision Scope

The objective lens is operating at a 1:1.2 aperture with 3.1x image magnification for nocturnal viewing. The image tube gain is 15,000, whatever this means. The Night vision gadget needs two 2 AA batteries. It measures 7.2 by 2.4 by 3.2 inches ...
https://i4u.com/1666/night-owl-cyclops-compact-night-vision-scope

*  Bell and Howell DNV900HD Camcorder 1080p Infrared HD 16MP 3.0 LCD Night Vision Motion Detection Reviews - alaTest.com

Read 16 reviews and find the lowest price for the Bell and Howell DNV900HD Camcorder 1080p Infrared HD 16MP 3.0 LCD Night Vision Motion Detection. Overall, this Camcorder is rated 77/100 Good.
alatest.com/reviews/camcorder-reviews/bell-and-howell-dnv900hd-camcorder-1080p-infrared-hd-16mp-3-0-lcd-night-vision-motion-detection/po3-181361446,21/

*  Wholesale 2to1 Touch Key 7 inch TFT LCD Wired Color Night Vision Video Door Phone | ineSun.com

Online wholesale 2to1 Touch Key 7 inch TFT LCD Wired Color Night Vision Video Door Phone from China Wired Video Door Phone wholesale directory at ineSun.com!
inesun.com/2to1-Touch-Key-7-inch-TFT-LCD-Wired-Color-Night-Vision-Video-Door-Phone--20120.html

*  UFO spotted through night vision boggles by military combat instructor | Daily Star

THIS is the extraordinary moment a military worker caught sight of a UFO flying through the night sky through his night vision goggles.
dailystar.co.uk/news/latest-news/399098/Military-worker-spots-UFO-through-night-vision-goggles

*  Lieder 480TVL 1/4 SHARP CCD 10 LED IR Night Vision Dome Color Security Camera AVS-C358Y - DinoDirect.com

Shop lieder 480tvl 1/4 sharp ccd 10 led ir night vision dome color security camera avs-c358y free shipping online at DinoDirect store.
dinodirect.com/480TVL-1-4-SHARP-CCD-10-LED-IR-Night-Vision-Dome-Color-Security-Camera-AVS-C358Y.html

*  SA Photonics Develops an Advanced Digital Night Vision System | Business Wire

SA Photonics develops a wide field of view, high resolution digital night vision head mounted display for pilots of fixed-wing aircraft and rotorcraft
businesswire.com/news/home/20110419005767/en/SA-Photonics-Develops-Advanced-Digital-Night-Vision

*  BNVD-SG UL Ultra Lightweight Night Vision Binocular - Single Gain - Night Vision Devices

The NVD BNVD-SG UL incorporates new high performance optics. These optics are much lighter and offer higher performance than standard AN/PVS-14 optics.
nvdevices.com/products/night-vision/sg-ul-bnvd-ultra-lightweight-night-vision-binocular-single-gain/

*  Original SYSD SY905FC11 Video Door Phone Doorbell Intercom Kit 900TVL IR Night Vision Camera 9 Inch TFT Screen Monitor - Blog...

For just US$115.88 , buy SYSD SY905FC11 Video Door Phone Doorbell Intercom Kit 900TVL IR Night Vision Camera 9 Inch TFT Screen Monitor from the China wholesale webshop ...
blogpower.cl/original-sysd-sy905fc11-video-door-phone-doorbell-intercom-kit-900tvl-ir-night-vision-camera-9-inch-tft-screen-monitor/

*  ATN NVM-14 Gen 4 Night Vision Monocular - Prima Sport Optics - ecplaza.net

Offer Prices USD 3,058.12 The ATN NVM-14 Generation 4 is a hand-held, head-mounted, helmet-mounted, or weapon-mounted Night Vision System that enables walking, driving, weapon firing, short-range surveillance, map reading, vehicle maintenance, and...
https://ecplaza.net/products/atn-nvm-14-gen-4-night_3961841

*  HD Night Vision Camera Watch

It's time to get all secret agenty with the Night Vision Camera Watch, piercing the darkness with your hi-tech goodies to get covert photos and video of people
https://geekalerts.com/hd-night-vision-camera-watch/

*  BNVD-DG-SGFK Night Vision Binocular Special Ground Forces Kit - Dual Gain - Night Vision Devices

Our BNVD-DG Special Ground Forces Kit combines those accessories most often required for special ground operations into one easy to purchase package.
nvdevices.com/products/night-vision/bnvd-dg-sgfk-night-vision-binocular-special-ground-forces-kit/

*  MNVD Night Vision Monocular - Night Vision Devices

The MNVD is a revolutionary new concept that combines the best features of a monocular with the ability to be converted into a fully functional binocular.
nvdevices.com/products/night-vision/mnvd-night-vision-monocular/

*  MNVDG Night Vision Monocular - Night Vision Devices

The MNVDG is a revolutionary new concept that combines all the best features of a monocular with the ability to be converted into a fully functional binocular.
nvdevices.com/products/night-vision/mnvdg-night-vision-monocular/

*  Armasight AVENGER GEN 2+ ID Improved Definition Night Vision Monocular with 3X Magnification, Black

DESCRIPTION: The Armasight Avenger ID is a high-tech, tough and durable multi-use night vision monocular that delivers great Gen 2+ performance at the lowest possible cost. Packed
theoutdoorstores.com/armasight-avenger-gen-2-id-improved-definition-night-vision-monocular/

*  Wiggle | Altura Night Vision Waterproof Winter Cycling Gloves | Winter Gloves

Buy your Altura Night Vision Waterproof Winter Cycling Gloves - Winter Gloves from Wiggle. Our price . Free worldwide delivery available.
wiggle.co.uk/altura-night-vision-waterproof-winter-cycling-gloves/

*  Deer Night Vision | Bowhunting.Net

What Happens:. All vision is initiated when light entering the pupil strikes the retina. Light is registered on a light sensitive layer of tissue at the back of the eye that is analogous to the film in a camera. The retina contains two kinds of light-sensitive receptor cells, rods and cones. The cones are responsible for day-time vision and color vision. Rods are responsible for vision in dim light. The central region of the human eye (the fovea) on which we depend on most for vision is tightly packed with cones but contains no rods. The rest of the human retina contains both rods and cones. The ratio of rods to cones increases in the periphery of the human retina.. Deer specifically, but all ungulates (hoofed animals) also have both rods and cones but rods predominate (even in the central area) making up well over 90 percent of the total photoreceptors over the entire area of the retina. The rods are incredibly sensitive to ...
bowhunting.net/2012/05/deer-night-vision/

Low vision assessment: Low vision is both a subspeciality and a condition. Optometrists and Ophthalmologists after their training may undergo further training in Low vision assessment and management.Operation Eyesight Universal: Operation Eyesight Universal is a Canada-based international development organisation, founded in 1963. It works to prevent avoidable blindness and to cure blindness that is treatable.Landolt CGene therapy for color blindness: Gene therapy for color blindness is an experimental gene therapy aiming to convert congenitally colorblind individuals to trichromats by introducing a photopigment gene that they lack. Though partial color blindness is considered only a mild disability and is controversial whether it is even a disorder, it is a condition that affects many people, particularly males.Binocular vision: Binocular vision is vision in which creatures having two eyes use them together. The word binocular comes from two Latin roots, bini for double, and oculus for eye.LogMAR chart: A LogMAR chart comprises rows of letters and is used by ophthalmologists and vision scientists to estimate visual acuity. This chart was developed at the National Vision Research Institute of Australia in 1976, and is designed to enable a more accurate estimate of acuity as compared to other charts (e.Tactical light: A tactical light is a flashlight used in conjunction with a firearm to aid low light target identification, allowing the marksman to simultaneously aim and illuminate the target. Tactical lights can be handheld or mounted to the weapon with the light beam parallel to the bore.Blind People's Association: The Blind People’s Association (BPA) is an organisation in India which promotes comprehensive rehabilitation of persons with all categories of disabilities through education, training, employment, community based rehabilitation, integrated education, research, publications, human resource development and other innovative means.Farnsworth Lantern Test: The Farnsworth Lantern Test, or FALANT, is a test of color vision originally developed specifically to screen sailors for shipboard tasks requiring color vision, such as identifying signal lights at night. It screens for red-green deficiencies, but not the much rarer blue color deficiency.Meridian (perimetry, visual field): Meridian (plural: "meridians") is used in perimetry and in specifying visual fields. According to IPS Perimetry Standards 1978 (2002): "Perimetry is the measurement of [an observer's] visual functions ...Rimless eyeglasses: Rimless eyeglasses, are a type of eyeglasses in which the lenses are mounted directly to the bridge and/or temples. The style is divided into two subtypes: three piece glasses are composed of lenses mounted to a bridge and two separate temple arms, while rimways (also called cortlands) feature a supporting arch that connects the temples to the bridge and provides extra stability for the lenses.Braille technology: Braille technology is assistive technology which allows blind or visually impaired people to do common tasks such as writing, browsing the Internet, typing in Braille and printing in text, engaging in chat, downloading files, music, using electronic mail, burning music, and reading documents. It also allows blind or visually impaired students to complete all assignments in school as the rest of sighted classmates and allows them take courses online.AmblyopiaKorte's law: In psychophysics, Korte's law, also known more completely as Korte's third law of apparent motion, is an observation relating the phenomenon of apparent motion to the distance and duration between two successively presented stimuli. It was originally proposed in 1915 by Adolf Korte.Percolation threshold: Percolation threshold is a mathematical concept related to percolation theory, which is the formation of long-range connectivity in random systems. Below the threshold a giant connected component does not exist; while above it, there exists a giant component of the order of system size.Autorefractor: An autorefractor or automated refractor is a computer-controlled machine used during an eye examination to provide an objective measurement of a person's refractive error and prescription for glasses or contact lenses. This is achieved by measuring how light is changed as it enters a person's eye.Photopic vision: Photopic vision is the vision of the eye under well-lit conditions. In humans and many other animals, photopic vision allows color perception, mediated by cone cells, and a significantly higher visual acuity and temporal resolution than available with scotopic vision.Macula of retina: The macula or macula lutea (from Latin macula, "spot" + lutea, "yellow") is an oval-shaped pigmented area near the center of the retina of the human eye. It has a diameter of around .Neuro-ophthalmology: Neuro-ophthalmology is an academically-oriented subspecialty that merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that have manifestations in the visual system. Neuro-ophthalmologists initially complete a residency in either neurology or ophthalmology, then do a fellowship in the complementary field.OpsinStrabismusPlastic headlight restorationStereopsis: Stereopsis (from the Greek στερεο- [meaning "solid", and ὄψις] opsis, "appearance, [[visual perception|sight") is a term that is most often used to refer to the perception of depth and 3-dimensional structure obtained on the basis of visual information deriving from two eyes by individuals with normally developed binocular vision.Retinal regeneration: Retinal regeneration deals with restoring retinal function to vertebrates so impaired.Pediatric ophthalmology: Pediatric ophthalmology is a sub-speciality of ophthalmology concerned with eye diseases, visual development, and vision care in children.Age-Related Eye Disease Study: The Age-Related Eye Disease Study (AREDS) was a clinical trial sponsored by the National Eye Institute, one of the National Institutes of Health in the United States.A Randomized, Placebo-Controlled, Clinical Trial of High-Dose Supplementation With Vitamins C and E, Beta Carotene, and Zinc for Age-Related Macular Degeneration and Vision Loss.Photopigment: Photopigments are unstable pigments that undergo a chemical change when they absorb light. The term is generally applied to the non-protein chromophore moiety of photosensitive chromoproteins, such as the pigments involved in photosynthesis and photoreception.Congenital cataractMelanopsin: Melanopsin is a type of photopigment belonging to a larger family of light-sensitive retinal proteins called opsins and encoded by the gene Opn4. Two other opsins in the mammalian retina are both involved in the formation of visual images: rhodopsin and photopsin in the rod and cone photoreceptor cells, respectively.ScotomaPresbyopiaCanon EOS 5Biological motion: Biological motion is a term used by social and cognitive neuroscientists to refer to the unique visual phenomenon of a moving, animate object. Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints of the moving organism.Entoptic phenomena (archaeology): In archaeology, the term entoptic phenomena relates to visual experiences derived from within the eye or brain (as opposed to externally, as in normal vision). In this respect they differ slightly from the medical definition, which defines entoptic phenomena as only applying to sources within the eye, not the brain.Glare (vision): Glare is difficulty seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions.Grow lightCataract surgerySpalding MethodMonocular estimate method: The monocular estimate method or monocular estimation method is a form of dynamic retinoscopy widely used to objectively measure accommodative response.Tassinari JT.Sustainability marketing myopia: Sustainability marketing myopia is a term used in sustainability marketing referring to a distortion stemming from the overlooking of socio-environmental attributes of a sustainable product or service at the expenses of customer benefits and values. The idea of sustainability marketing myopia is rooted into conventional marketing myopia theory, as well as green marketing myopia.List of optometry schools: The following list of optometry schools covers many countries, although the list is not exhaustive. Internationally, optometry as a profession includes different levels of education.Micromirror device: Micromirror devices are devices based on microscopically small mirrors. The mirrors are Microelectromechanical systems (MEMS), which means that their states are controlled by applying a voltage between the two electrodes around the mirror arrays.Cortical blindnessPurtscher's retinopathy: Purtscher's retinopathy is a disease where part of the eye (retina) is damaged. Usually associated with severe head injuries, it may also occur with other types of trauma, such as long bone fractures, or with several non-traumatic systemic diseases.Blue colour works: A blue colour works () is a paintworks where blue paint for use in glassmaking is produced. Usually the pigment, cobalt blue, needed for this purpose, was manufactured from cobalt-containing ore as in the case of the factories listed below.Flicker (screen): Flicker is a visible fading between cycles displayed on video displays, especially the refresh interval on cathode ray tube (CRT) based computer screens. Flicker occurs on CRTs when they are driven at a low refresh rate, allowing the brightness to drop for time intervals sufficiently long to be noticed by a human eye – see persistence of vision and flicker fusion threshold.Guiding Eyes for the Blind: Yorktown Heights, New YorkNeuropathy, ataxia, and retinitis pigmentosaMicroneurography: Microneurography is a neurophysiological method employed by scientists to visualize and record the normal traffic of nerve impulses that are conducted in peripheral nerves of waking human subjects. The method has been successfully employed to reveal functional properties of a number of neural systems, e.Photovoltaic retinal prosthesis: Photovoltaic retinal prosthesis is a technology for restoring sight to blind patients suffering from degenerative retinal diseases. In retinal degenerative diseases such as Retinitis Pigmentosa and Age-Related Macular Degeneration, patients loss ‘image capturing’ photo-receptors, but, neurons in the ‘image-processing’ inner retinal layers are relatively well preserved.X-linked congenital stationary night blindnessEye injuryPhospheneSubatomic scale: The subatomic scale is the domain of physical size that encompasses objects smaller than an atom. It is the scale at which the atomic constituents, such as the nucleus containing protons and neutrons, and the electrons, which orbit in spherical or elliptical paths around the nucleus, become apparent.Charles D. Phelps: Charles Dexter Phelps (September 16, 1937 – September 13, 1985) was a prominent American medical doctor, professor, and researcher in the field of ophthalmology. The clinical studies he oversaw contributed to significant advances in the scientific understanding and surgical and pharmacological treatment of glaucoma.Optic neuritisExtended physiological proprioception: Extended physiological proprioception (EPP) is a concept pioneered by D.C.List of optical illusions: This is a list of optical illusions.Convergence of measures: In mathematics, more specifically measure theory, there are various notions of the convergence of measures. For an intuitive general sense of what is meant by convergence in measure, consider a sequence of measures μn on a space, sharing a common collection of measurable sets.Auditory illusion: An auditory illusion is an illusion of hearing, the aural equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or "impossible" sounds.Perspective distortion (photography): Perspective correction}}Diabetic retinopathy: ( )Cue stick: A cue stick (or simply cue, more specifically pool cue, snooker cue, or billiards cue), is an item of sporting equipment essential to the games of pool, snooker and carom billiards. It is used to strike a ball, usually the .Chemical imaging: Chemical imaging (as quantitative – chemical mapping) is the analytical capability to create a visual image of components distribution from simultaneous measurement of spectra and spatial, time information.http://www.Spasm of accommodation: A spasm of accommodation (also known as an accommodation, or accommodative spasm) is a condition in which the ciliary muscle of the eye remains in a constant state of contraction. Normal accommodation allows the eye to "accommodate" for near-vision.Fairness to Contact Lens Consumers Act: The Fairness to Contact Lens Consumers Act (, 117 Stat. 2025, 2026, 2027, 2028 and 2029, codified at et seq.Optic disc pit: An optic disc pit is a congenital excavation (or regional depression) of the optic nerve head resulting from a malformation during development of the eye. Optic pits are important because they are associated with posterior vitreous detachments (PVD) and even serous retinal detachments.

(1/654) CRE-mediated gene transcription in neocortical neuronal plasticity during the developmental critical period.

Neuronal activity-dependent processes are believed to mediate the formation of synaptic connections during neocortical development, but the underlying intracellular mechanisms are not known. In the visual system, altering the pattern of visually driven neuronal activity by monocular deprivation induces cortical synaptic rearrangement during a postnatal developmental window, the critical period. Here, using transgenic mice carrying a CRE-lacZ reporter, we demonstrate that a calcium- and cAMP-regulated signaling pathway is activated following monocular deprivation. We find that monocular deprivation leads to an induction of CRE-mediated lacZ expression in the visual cortex preceding the onset of physiologic plasticity, and this induction is dramatically downregulated following the end of the critical period. These results suggest that CRE-dependent coordinate regulation of a network of genes may control physiologic plasticity during postnatal neocortical development.  (+info)

(2/654) Selective pruning of more active afferents when cat visual cortex is pharmacologically inhibited.

Activity-dependent competition is thought to guide the normal development of specific patterns of neural connections. Such competition generally favors more active inputs, making them larger and stronger, while less active inputs become smaller and weaker. We pharmacologically inhibited the activity of visual cortical cells and measured the three-dimensional structure of inputs serving the two eyes when one eye was occluded. The more active inputs serving the open eye actually became smaller than the deprived inputs from the occluded eye, which were similar to those in normal animals. These findings demonstrate in vivo that it is not the amount of afferent activity but the correlation between cortical and afferent activity that regulates the growth or retraction of these inputs.  (+info)

(3/654) Optical imaging of functional domains in the cortex of the awake and behaving monkey.

As demonstrated by anatomical and physiological studies, the cerebral cortex consists of groups of cortical modules, each comprising populations of neurons with similar functional properties. This functional modularity exists in both sensory and association neocortices. However, the role of such cortical modules in perceptual and cognitive behavior is unknown. To aid in the examination of this issue we have applied the high spatial resolution optical imaging methodology to the study of awake, behaving animals. In this paper, we report the optical imaging of orientation domains and blob structures, approximately 100-200 micrometer in size, in visual cortex of the awake and behaving monkey. By overcoming the spatial limitations of other existing imaging methods, optical imaging will permit the study of a wide variety of cortical functions at the columnar level, including motor and cognitive functions traditionally studied with positron-emission tomography or functional MRI techniques.  (+info)

(4/654) Monocular focal retinal lesions induce short-term topographic plasticity in adult cat visual cortex.

Electrophysiological recording in primary visual cortex (VI) was performed both prior to and in the hours immediately following the creation of a discrete retinal lesion in one eye with an argon laser. Lesion projection zones (LPZs; 21-64 mm2) were defined in the visual cortex by mapping the extent of the lesion onto the topographic representation in cortex. There was no effect on neuronal responses to the unlesioned eye or on its topographic representation. However, within hours of producing the retinal lesion, receptive fields obtained from stimulation of the lesioned eye were displaced onto areas surrounding the scotoma and were enlarged compared with the corresponding field obtained through the normal eye. The proportion of such responsive recording sites increased during the experiment such that 8-11 hours post-lesion, 56% of recording sites displayed neurons responsive to the lesioned eye. This is an equivalent proportion to that previously reported with long-term recovery (three weeks to three months). Responsive neurons were evident as far as 2.5 mm inside the border of the LPZ. The reorganization of the lesioned eye representation produced binocular disparities as great as 15 degrees, suggesting interactions between sites in VI up to 5.5 mm apart.  (+info)

(5/654) Monocular occlusion cues alter the influence of terminator motion in the barber pole phenomenon.

The influence of monocular occlusion cues on the perceived direction of motion of barber pole patterns is examined. Unlike previous studies that have emphasized the importance of binocular disparity, we find that monocular cues strongly influence the perceived motion direction and can even override binocular depth cues. The difference in motion bias for occluders with and without disparity cues is relatively small. Additionally, although 'T-junctions' aligned with occluders are particularly important, they are not strictly necessary for creating a change in motion perception. Finally, the amount of motion bias differs for several stimulus configurations, suggesting that the extrinsic/intrinsic classification of terminators is not all-or-none.  (+info)

(6/654) Dynamics of horizontal vergence movements: interaction with horizontal and vertical saccades and relation with monocular preferences.

We studied the dynamics of pure vergence shifts and vergence shifts combined with vertical and horizontal saccades. It is known from earlier studies that horizontal saccades accelerate horizontal vergence. We wanted to obtain a more complete picture of the interactions between version and vergence. Therefore we studied pure version (horizontal and vertical), pure vergence (divergence and convergence) and combinations of both in five adult subjects with normal binocular vision and little phoria (< 5 degrees). The visual targets were LED's in isovergence arrays presented at two distances (35 and 130 cm) in a dimly lit room. Two targets were continuously lit during each trial and gaze-shifts were paced by a metronome. The two subjects with a strong monocular preference made vergence eye movements together with small horizontal saccades during pure vergence tasks. The other subjects, who did not have a strong monocular preference, made pure vergence movements (without saccades). These findings, suggest that monocular preferences influence the oculomotor strategy during vergence tasks. Vergence was facilitated by both horizontal and vertical saccades but vergence peak-velocity during horizontal saccades was higher than during vertical saccades.  (+info)

(7/654) Spatial characteristics of cerebral polyopia: a case study.

A 41-year-old woman showed bilateral monocular polyopia and an incomplete, right-sided homonymous hemianopia following bilateral cerebral strokes confirmed by neuroimaging. She was tested with briefly-presented visual stimuli to determine whether her polyopic images varied with visual field position of stimuli which evoked them. Stimuli close to her scotoma elicited polyopic images at shorter latency and higher probability than did stimuli more distant from it. RS could maintain stable fixation on small stimuli, suggesting that eye movements were not responsible for her polyopia. We discuss the possibility that cerebral polyopia is due to recoding of visual receptive fields in primary visual cortex and that bilateral occipital lesions are a causative factor in the genesis of the disorder.  (+info)

(8/654) Sensory regulation of immediate-early genes c-fos and zif268 in monkey visual cortex at birth and throughout the critical period.

The postnatal development of ocular dominance columns (ODCs) in monkey visual cortex provides an exquisite model for studying mechanisms of experience-guided neuronal plasticity. While the presence of columns at birth in Old World monkeys is now well established, it remains unclear whether cortical neurons at this early stage are capable of modulating gene expression in response to changing sensory conditions. Using a set of monocular deprivation and stimulation protocols, we examined activity-driven expression of the immediate-early genes (IEGs) c-fos and zif268 during the critical period of development. We observed well-delineated patterns of ODCs produced by sensory regulation of both IEGs throughout the critical period, starting as early as the first postnatal day. The expression levels are similar in layers II/II, IVC and VI throughout development, with no selective decline in the thalamorecepient layer (layer IVC) of adult monkeys. A narrow strip of non-columnar c-Fos expression was observed at the border of layers IVC and V. Our results show that neurons in monkey visual cortex are equipped at birth with the molecular machinery for coupling sensory inputs to active genomic responses and that this responsivity extends throughout the critical period. The findings are discussed within the context of a possible role for IEGs in sensory-driven cortical plasticity during development.  (+info)



Optics


  • Explore the night with the KONUSPY-6 5x Digital Night Vision Monocular from Konus Optics . (bhphotovideo.com)

magnification


  • Big eyepiece antireflection coated blue film, the vision, viewing comfort Large objective lens to increase the amount of light, the image is more clear and bright All-optical glass lenses, all surfaces of the multilayer broadband coating Imaging does not cast no distortion, viewing pleasure Offers an 35x magnification and a 3.25mm objective diameter. (theoutdoorstores.com)

binoculars


  • Compared to other Binoculars the Night Owl iGEN 20/20 Day/Night Vision Monocular with Image Caputre (3x) is awarded an overall alaScore™ of 81/100 = Very good quality. (alatest.com)

Features


  • The monocular also features an attached hand strap to allow an easy and secure one-handed operation. (bhphotovideo.com)

great


  • Have you ever seen the moon up close, or the consolation, M42, the Orion Nebula, or wished you could see something at a great distance, like having the vision of an eagle? (brookstone.com)
  • Combine this with a generation 1 light intensifier and you've got a great value in night vision. (sportsmansguide.com)
  • Long-lasting night-vision function at a great price. (sportsmansguide.com)
  • The Armasight Avenger ID is a high-tech, tough and durable multi-use night vision monocular that delivers great Gen 2+ performance at the lowest possible cost. (theoutdoorstores.com)

night


  • With this monocular, you will be able to observe night scenery, take images, and record 10-minute videos. (bhphotovideo.com)
  • ATN® 3 x MO4 - 1: Get generation 1 night vision and "Smart" technology. (sportsmansguide.com)
  • You must be 18 or older to purchase Night Vision. (sportsmansguide.com)
  • Night Vision cannot be shipped Parcel Post. (sportsmansguide.com)
  • Please check your State, County and City laws for restrictions before ordering Night Vision. (sportsmansguide.com)
  • What is most amazing about this device is that, unlike ordinary night vision, the Ranger can be used for daytime, as well as nighttime, operation without damaging the device. (ableammo.com)
  • The Armasight Avenger ID is a night vision workhorse that will exceed the performance requirements of the most demanding professionals or casual night vision users. (theoutdoorstores.com)
  • Bushnell LYNX Gen 1 Night Vision Binocul. (theoutdoorstores.com)
  • ATN Night Spirit-2 Gen 2+ Night Vision M. (theoutdoorstores.com)
  • alaTest has collected and analyzed 10 reviews of Night Owl iGEN 20/20 Day/Night Vision Monocular with Image Caputre (3x). (alatest.com)
  • iGen 20/20¿ IC Night Vision Viewer is superior in quality, resolution and clarity. (alatest.com)

uses


  • Brookstone is proud to carry a wide assortment of vision apparatuses for a variety of uses. (brookstone.com)