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Visual Function and Cortical Organization in Carriers of Blue Cone
Visual Function and Cortical Organization in Carriers of Blue Cone

... dimensions of the visual system. Several studies have supported this view by establishing that the development of different visual components are indeed interdependent [6,9–11]. It has been hypothesized that the cone mosaic may be the key factor that leads to the variability observed in higher struc ...
Eye Problems - Canis Maximus
Eye Problems - Canis Maximus

... eye clean and eliminating the cause of the conjunctivitis with appropriate medication are keys to control." Keratitis- "Chronic superficial keratitis, also know as degenerative pannus, occurs primarily in German Shepherds but occasionally in other breeds," says Dr. Paul Gerding, also a veterinary op ...
UCL Institute of Ophthalmology wins Queen`s Anniversary Prize
UCL Institute of Ophthalmology wins Queen`s Anniversary Prize

... “Welcome to the second issue of Visibility. Since our last issue there has been much to celebrate at Moorfields and the UCL Institute of Ophthalmology, all of which helps to reinforce our importance as one of the world’s leading centres for eye research and education. Moorfields’ wide clinical and p ...
Variations in image optical quality of the eye and the sampling limit
Variations in image optical quality of the eye and the sampling limit

... Data Processing and Analysis Image analysis of the photoreceptor mosaic was performed using Image J (version 1.45a, U.S. National Institutes of Health). For each eye, the acquired images were stitched together to create a larger montage (approximately 9 degrees  9 degrees) of the photoreceptor mosa ...
Transvitreal Subretinal Injection
Transvitreal Subretinal Injection

... – Also thought that vitrectomy would facilitate bleb formation and allow larger volumes to be injected. – Additional studies demonstrated this was not the case. ...
Figuring Space by Time. Neuron Vol. 32, 185-201.
Figuring Space by Time. Neuron Vol. 32, 185-201.

... both employ movements of the sensory organs during active sensing epochs. These movements prevent receptor adaptation when the stimulus is stationary, which allows the sensation of a stationary environment and thus provides a significant evolutionary advantage over species that can sense only extern ...
My Last nerve - eyespecialtygroup.com
My Last nerve - eyespecialtygroup.com

... The facial nerve (CNVII) innervates the obicularis oculi, frontalis, procerus, and corrugator supercilii muscles, and supports eyelid protraction. The temporal and zygomatic branches of the facial nerve supply the obicularis oculi, the main eyelid protractor. The facial nerve also supplies the corru ...
Diabetes: A Reference for the Primary Eyecare Clinician
Diabetes: A Reference for the Primary Eyecare Clinician

... exact physiology of venous beading in diabetic retinopathy, although some scientists have suggested that it may be an adaptation to increased blood flow. More pronounced venous changes may be a result of metabolic acidosis from peripheral ischemia secondary to capillary occlusion. ...
Visual System Disorders
Visual System Disorders

... In CRAO, unilateral visual loss occurs rapidly. Findings include the pupil not reacting to light and funduscopy showing ischemic retina appearing pale (white) with normal red-colored choroid reflecting through fovea (cherry-red spot); optic atrophy develops later. In some cases, retinal embolus that ...
- Eye, Brain, and Vision
- Eye, Brain, and Vision

... fitted, and vision is completely restored. The vision can even be better than it was before the cataracts developed, because all lenses yellow with age, and their removal results in a sky of marvelous blue seen otherwise only by children and young adults. It would seem that visual deprivation in chi ...
Carbonic anhydrase isoenzymes CA I and CA II in the human
Carbonic anhydrase isoenzymes CA I and CA II in the human

... in any tissue, since all histochemical staining was inhibited by 10 nM acetazolamide (see Methods). It should be noted that the immunological method does not detect the membrane-bound CA IV, which is immunologically different6 from the cytoplasmic forms. With the histochemical method, on the other h ...
Retinal Vein Occlusions
Retinal Vein Occlusions

... Neovascularization of the iris may develop as early as 2 weeks after central retinal vein occlusion or as late as 2½1/2 years Neovascularization of the iris will develop in almost all patients within the first year, but usually in the first 3 months.89 Symptomatically, patients complain of tearing, ...
optic neuritis recent concepts
optic neuritis recent concepts

... neuritis such as sarcoidosis, syphilis or an idiopathic autoimmune optic neuritis that is steroid-responsive. 28% of patients developed recurrent optic neuritis which was associated with oral prednisone. As a result, oral steroids is contraindicated in the management of acute optic neuritis. Since o ...
The Msh-\\ke homeobox genes define domains in the
The Msh-\\ke homeobox genes define domains in the

... Fig. 2B). The conserved hexapeptide (Ile/Val-Tyr-ProTrp-Met-Arg) shared by many of the homeoboxcontaining genes, is retained only as the dipeptide ProTrp in the Hox-8.1 gene. Linkage analysis of the Hox-8.1 gene The majority of the homeobox-containing genes reside in one of four tightly linked multi ...
What is a Cataract
What is a Cataract

... • The lens, where cataracts form, is positioned behind the colored part of your eye (iris). The lens focuses light that passes into your eye, producing clear, sharp images on the retina — the light-sensitive membrane on the back inside wall of your eyeball that functions like the film of a camera. ...
Acquired Maculopathy
Acquired Maculopathy

...  These changes are commonly observed in the eyes of most elderly persons to some degree  Cell death and functional loss  Only in some individuals do these age related changes progress to this stage  Transition from normal aging to disease (with a loss of functional vision)  Drusen are players i ...
Mast cells in human optic nerve.
Mast cells in human optic nerve.

... needed for pathological diagnosis for research purposes. The eyes were fixed in formalin, embedded in paraffin, and sectioned according to routine methods. All had at least 1 mm of optic nerve present. Individual sagittal sections containing the optic disk and contiguous nerve were incubated with na ...
Photoacoustic ocular imaging
Photoacoustic ocular imaging

... blood photoacoustic signal and the depth of penetration. However, since the melanin absorption is significant at this wavelength, significant photoacoustic signals are observed from the iris and the retinal pigment epithelium, an epithelial monolayer between the retina and the choroid. The anatomy o ...
Eyes - The George Veterinary Group
Eyes - The George Veterinary Group

... external trauma, we see bleeding within the anterior chamber (hyphaema) (3). Although the bleed often resolves in time, these cases obviously need seeing to ascertain why it has happened and whether there is any ongoing damage. Within the normal anterior chamber are structures called the Granula Iri ...
Retina Retinal Imaging
Retina Retinal Imaging

... et al. did not observe this relationship between peripheral ischemia and central macular thickness, but the authors postulate this may have been due to the higher number of patients with macular ischemia included in their study.15 They did note a relationship between capillary nonperfusion in the pe ...
Central retinal thickness is positively correlated with
Central retinal thickness is positively correlated with

... Received 7 August 2005; accepted in revised form 20 October 2005 Available online 27 December 2005 ...
How to Diagnose Ocular Abnormalities with Ultrasound
How to Diagnose Ocular Abnormalities with Ultrasound

... is recognized by a thin hypoechoic rim within the lens capsule. Mature acquired cataracts may vary somewhat in their sonographic appearance. Most cataracts demonstrate a thickened echogenic lens capsule with or without irregular margins. The interior of the cataractous lens may be filled with echoge ...
Ultrahigh-resolution high-speed retinal imaging using spectral-domain optical coherence tomography
Ultrahigh-resolution high-speed retinal imaging using spectral-domain optical coherence tomography

... same SNR, either A-line rate or axial scan length should be decreased, or the power incident on the sample should be increased. If the dwell time of the imaging spot on the retina is kept short, ANSI standards allow an increase of sample power. [7] Short dwell times can be achieved if the OCT beam i ...
Retinitis Pigmentosa - University of Michigan Kellogg Eye Center
Retinitis Pigmentosa - University of Michigan Kellogg Eye Center

... the condition, this is actually uncommon for people with RP. It is more likely that in the later stages of disease a patient would be considered “legally blind.” This is defined as having best corrected vision equal to or worse than 20/200 or less than 20 degrees on a visual field in both eyes. If l ...
الشريحة 1
الشريحة 1

... * With both eyes open , the red fixation object is now stimulating both foveae , which are corresponding retinal points . The black object is now not only stimulating the temporal retinal elements in the right eye but also the nasal elements of the left eye . The right eye therefore projects the obj ...
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Retina



The retina (/ˈrɛtɪnə/ RET-i-nə, pl. retinae, /ˈrɛtiniː/; from Latin rēte, meaning ""net"") is the third and inner coat of the eye which is a light-sensitive layer of tissue. The optics of the eye create an image of the visual world on the retina (through the cornea and lens), which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centres of the brain through the fibres of the optic nerve.In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS) and is actually brain tissue. It is the only part of the CNS that can be visualized non-invasively.The retina is a layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the intrinsically photosensitive ganglion cell, is important for reflexive responses to bright daylight.Neural signals from the rods and cones undergo processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.
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