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  • retina
  • We now know that this is the function of the retina, with the lens serving as a conduit of light transmission and focus to the retina. (utah.edu)
  • The lens can change shape with the aid of the ciliary muscles, thereby changing the focal distance to the retina and bringing the image into sharp focus on the retina. (utah.edu)
  • A human eyeball cut in half to show the lens and the passage of light through it from the object ahead to the focus on the retina. (utah.edu)
  • The crystalline lens , or lens, is a bi-convex structure in the eye that is transparent and which works with the cornea to refract light to focus on the retina. (advancedvisioncare.co.uk)
  • The lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. (wikipedia.org)
  • The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. (wikipedia.org)
  • His work led to much discussion in 16th century Europe over whether the principal organ of sight is the traditional Galenic crystalline humour or the Averroist aranea, which in turn led to the discovery that the retina is the principal organ of sight. (wikipedia.org)
  • Finally, the retina transmits nutrients to the lenses themselves. (wikipedia.org)
  • Rufus was the first to recognise a two-chambered eye, with one chamber from cornea to lens (filled with water), the other from lens to retina (filled with an egg white-like substance). (wikipedia.org)
  • Proteins
  • Fernald also did research on eye evolution, showing that photoreceptor proteins have an ancient origin predating vision while lens proteins have arisen many times from different sources in different animal lineages. (wikipedia.org)
  • capsule of t
  • One embodiment of the invention is an ocular drug delivery method by penetrating at least the outer capsule of the lens with a fine conduit that creates a self-sealing aperture when it is removed, then introducing a drug into the lens through this aperture. (google.com.au)
  • visualization
  • Early anatomists viewed the lens as the location of meaningful visualization. (utah.edu)
  • We used a new SS-OCT laboratory prototype designed to enhance the visualization of the crystalline lens and imaged the entire anterior segment of both eyes in two groups of participants: patients scheduled to undergo cataract surgery, n = 17, age range 36 to 91 years old, and volunteers without visual complains, n = 14, age range 20 to 81 years old. (arvojournals.org)
  • fibers
  • As the secondary lens fibers elongate from the equator, they form Y-shaped sutures by meeting anteriorly and posteriorly during fetal growth. (utah.edu)
  • Lower section is of the posterior lens capsule, plc and cortical fibers (cf). (utah.edu)
  • The lens is held in place by zonular fibers, otherwise known as the zonules of Zinn (Fig. 4). (utah.edu)
  • The capsule is very elastic and so allows the lens to assume a more globular shape when not under the tension of the zonular fibers, which connect the lens capsule to the ciliary body. (wikipedia.org)
  • The lens fibers form the bulk of the lens. (wikipedia.org)
  • The lens fibers stretch lengthwise from the posterior to the anterior poles and, when cut horizontally, are arranged in concentric layers rather like the layers of an onion. (wikipedia.org)
  • The lens fibers are linked together via gap junctions and interdigitations of the cells that resemble "ball and socket" forms. (wikipedia.org)
  • The lens is split into regions depending on the age of the lens fibers of a particular layer. (wikipedia.org)
  • Mature lens fibers have no organelles or nuclei. (wikipedia.org)
  • spherical
  • The cornea has greater refractive power which is static, but the lens is a unique biological structure that relies on an extraordinarily intricate arrangement of highly specialized cells to produce a gradient of refractive index that allows for remarkable dynamic focusing of an image with minimal spherical or chromatic aberration . (springer.com)
  • Conic and spherical functions were applied to anterior and posterior lens surfaces for central 6mm and 3mm zones, respectively. (arvojournals.org)
  • Corneal and lens surface elevations were analyzed by means of RMS (high order aberrations (HOAs), astigmatism, coma, trefoil and spherical). (arvojournals.org)
  • Spherical aberration showed higher changes with accommodation in the anterior lens surface (x2.5 vs x1.15). (arvojournals.org)
  • As opposed to Galen's more mathematical conception of flat-like lens, Hunayn opts for a more spherical shape which allows for a larger field of vision. (wikipedia.org)
  • post-mortem time
  • Measurements were performed on 13 lenses from 8 cynomolgus monkey eyes obtained as part of a tissue-sharing protocol (age: 5.7 to 12.4 years, post-mortem time: 37+/-17 hours). (arvojournals.org)
  • Crystalline lenses (n = 41, aged 10 months-88 years, median post-mortem time 25 hours (interquartile range, 19-34 hours)) were isolated from eyes received from the Ramayamma International Eye Bank, Hyderabad, India. (arvojournals.org)
  • cataract formation
  • 13 . A method that minimizes cataract formation when an agent is provided to an ocular lens, the method comprising piercing the lens with a needle of 30 gauge or thinner, introducing an agent into the lens through the needle, and withdrawing the needle from the lens. (google.com.au)
  • Because of the risk of inducing cataract formation, penetrating the lens capsule to introduce drugs or other agents into the lens has not been favorably considered. (google.com.au)
  • A firm understanding of the embryology and development of the lens will provide great insight into the pathology associated with cataract formation. (utah.edu)
  • surfaces
  • Before and after cataract surgery, the distribution of tilt magnitude and orientation of the lens or IOL were investigated using a prototype of IOLMaster700 (Carl Zeiss Meditec AG, Germany).Tilt orientation axis and tilt magnitude were derived from fitting a plane to 3D points sampled from 18 parabolas that were fitted to lens surfaces of 18 B-scans for each eye. (arvojournals.org)
  • Astigmatism, coma and trefoil changed with accommodation by a factor of x1.1, x1.3 and x1.4 respectively in both lens surfaces. (arvojournals.org)
  • The lenses of polarized sunglasses reduce glare reflected at some angles off shiny non-metallic surfaces, such as water. (wikipedia.org)
  • GRIN
  • A human eye model is proposed using a single equation for GRIN profile representation in crystalline lens. (osapublishing.org)
  • We present an optimization method to retrieve the gradient index (GRIN) distribution of the in-vitro crystalline lens from optical path difference data extracted from OCT images. (osapublishing.org)
  • The GRIN reconstruction method is based on a genetic algorithm that searches for the parameters of a 4-variable GRIN model that best fits the distorted posterior surface of the lens. (osapublishing.org)
  • osmotic
  • Researchers concluded that this osmotic swelling must be the result of an accumulation of abnormal metabolites or electrolytes in the lens. (wikipedia.org)
  • sagittal
  • There was a larger variation of the speed of sound across the sagittal profile in the young lens compared to the older lenses. (arvojournals.org)
  • The sagittal and coronal profiles of the lenses were imaged using a custom-built digital optical system based on the principle of shadowphotogrammetry. (arvojournals.org)
  • optical
  • Y. Huang and D. T. Moore, "Human Eye Modeling Using a Single Equation of Gradient Index Crystalline Lens for Relaxed and Accommodated States," in International Optical Design , Technical Digest (CD) (Optical Society of America, 2006), paper MD1. (osapublishing.org)
  • Optical and structural development of the crystalline lens in childhood. (wikipedia.org)
  • citation needed] Treatment is done by changing the optical magnification properties of the auxiliary optics (corrective lenses). (wikipedia.org)
  • Contact lenses may also provide a better optical magnification to reduce the difference in image size. (wikipedia.org)
  • When the disparity appears to vary across the visual field (field-dependent aniseikonia), as may be the case with an epiretinal membrane or retinal detachment, the aniseikonia cannot fully be corrected with traditional optical techniques like standard corrective lenses. (wikipedia.org)
  • aberrations
  • The mounted lenses were placed in a custom-built Laser-Ray Tracing (LRT) system designed to measure the lens power and aberrations on-axis and off-axis (Maceo Heilman et al, ARVO 2015). (arvojournals.org)
  • changes
  • We investigated the relationship among diabetes mellitus (DM), diabetic retinopathy (DMR) and crystalline lens changes by epidemiological surveys conducted in Japan, China, Taiwan, Iceland and Tanzania. (arvojournals.org)
  • There is some evidence that changes in the lens with age or accommodation have an effect on peripheral defocus. (arvojournals.org)
  • The purpose of this study was to quantify the peripheral defocus of the crystalline lens and its changes during simulation of accommodation in a lens stretching system. (arvojournals.org)
  • It's this lens which changes shape to help the eye alter its focal distance so it can focus on objects at varying distances. (advancedvisioncare.co.uk)
  • Rapid changes were observed in the young lenses in all dimensions obtained from the lens profiles, but at this time insufficient data are available to permit detailed analyses. (arvojournals.org)
  • Procedure
  • The use of a flexible IOL enables the lens to be rolled for insertion into the capsule through a very small incision, thus avoiding the need for stitches, and this procedure usually takes less than 30 minutes in the hands of an experienced ophthalmologist. (wikipedia.org)
  • IOL implantation carries several risks associated with eye surgeries, such as infection, loosening of the lens, lens rotation, inflammation and night time halos, but a systematic review of studies has determined that the procedure is safer than conventional laser eye treatment. (wikipedia.org)
  • shape
  • In the adult, the lens is typically circa 10 mm in diameter and has an axial length of about 4 mm, though it is important to note that the size and shape can change due to accommodation and because the lens continues to grow throughout a person's lifetime. (wikipedia.org)
  • One of the causes of the risks above is that the lens can rotate inside the eye if the PIOL is too short, if the eye was incorrectly measured, or because the sulcus has a slightly oval shape (the height is slightly smaller than the width). (wikipedia.org)
  • contact lens
  • The optimum design solution will depend on different parameters like cost, cosmetic implications, and if the patient can tolerate wearing a contact lens. (wikipedia.org)
  • function
  • The pseudophakic IOL provides the same light focusing function as the natural crystalline lens. (wikipedia.org)
  • They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. (wikipedia.org)
  • While both the conjuctiva and cornea provide protection with minimizing hindrance to the lenses, the uvea has an extra function of concentrating the pneuma exiting out of the eye to prevent it from being dissipated by light. (wikipedia.org)
  • glasses
  • The difference in magnification can also be eliminated by a combination of contact lenses and glasses (creating a weak telescope system). (wikipedia.org)
  • Effective IOL implants also entirely eliminate the need for glasses or contact lenses post-surgery for most patients. (wikipedia.org)
  • differentiation
  • The first stage of lens differentiation takes place when the optic vesicle, which is formed from outpocketings in the neural ectoderm, comes in proximity to the surface ectoderm. (wikipedia.org)
  • second
  • 5. The rays travel through the objective lens and are focused for the second Nomarski-modified Wollaston prism. (wikipedia.org)
  • The second most abundant intrinsic membrane protein of the lens fiber cell is MP19, so named for major lens protein having a molecular weight of 19.5 kD. (wikipedia.org)
  • light
  • Experimentally EBSD is conducted using a SEM equipped with an EBSD detector containing at least a phosphor screen, compact lens and low light CCD camera. (wikipedia.org)
  • image
  • Using new types of lenses and advanced imaging components, microOCT is able to image structures as small as one micrometer, revealing in intact tissue the detailed information provided by the prepared tissue slides of traditional pathology much faster and in three dimensions. (innovations-report.com)
  • The phosphor screen is located within the specimen chamber of the SEM at an angle off approximately 90° to the pole piece and is coupled to a compact lens which focuses the image from the phosphor screen onto the CCD camera. (wikipedia.org)
  • front
  • The appliances are mounted either on the eye as contact lenses or mounted in a frame or holder in front of the eye as spectacles or as a monocle. (wikipedia.org)
  • Devices
  • Other registered or licensed opticians manufacture lenses to their own specifications and design and manufacture spectacle frames and other devices. (wikipedia.org)