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PupilRetinaPupil DisordersTonic PupilReflex, PupillaryMydriaticsTropicamideRetinal Ganglion CellsMydriasisIrisPhotoreceptor Cells, VertebrateEuropean Continental Ancestry GroupLightRetinal Cone Photoreceptor CellsPhotoreceptor CellsRetinal DegenerationAfrican AmericansAnisocoriaElectroretinographyRetinal VesselsDark AdaptationMiosisRod OpsinsAccommodation, OcularRetinal Rod Photoreceptor CellsEye ProteinsRetinal DiseasesAmacrine CellsEyeVision, OcularRefraction, OcularPigment Epithelium of EyeAdie SyndromeEye ColorBlack SeaAberrometrySchoolsPhotic StimulationAdaptation, OcularFluorescent Antibody Technique, IndirectBlack PepperCyclopentolateRefractive ErrorsRetinal Bipolar CellsVisual AcuityVitreous BodyRetinal NeuronsChoroidUnited StatesCorneal TopographyRetinal PigmentsOptics and PhotonicsDiagnostic Techniques, OphthalmologicalRetinal Horizontal CellsRetinal Pigment EpitheliumGoldfishOphthalmoscopyRhodopsinDiabetic RetinopathyIntraocular PressureEye DiseasesNeurogliaRetinal DetachmentLightingFundus OculiMyopiaStudentsHispanic AmericansVisual FieldsTime FactorsFovea CentralisContinental Population GroupsMice, Inbred C57BLRetinal NeovascularizationOpsinsUveal DiseasesCimicifugaRetinitis PigmentosaCiliary BodyDarknessGlareAstigmatismLight Signal TransductionPresbyopiaFacultyGlaucomaColorVisual PathwaysOcular Physiological PhenomenaLens, CrystallineRod Cell Outer SegmentCorneaEye, ArtificialSoot
MaculaCenter of the retinaControls the size of the pupilIris and pupilOpticScleraHuman retinaPhotoreceptors in the retinaFocus light onto the retinaVitreousCone cellsFoveaAreas of the retinaRetinalNeurosensory retinaSensitive part of the retinaConstrictPassesDilate and contractDilatesVertical slit pupilEntersCentral retinaCataractsNervesMusclesDilationRods and cPosteriorCentreSensorySlitLarge PupilsMembraneMulti-layeredCornea is the clearSizeFocusesOuterNourishesReflective layerCiliarySightEye'sCat'sFloatersBlown pupilEyesTissueMacularChoroidBlood vesselsBlindnessCircularEyeballConverts lightAnisocoriaSharpnessWidenFelineExamineBackStructuresSmallNerve cellsPhotoreceptor cellsCells
Macula9
  • For precise tasks, light is focused on the centre of your retina, in an area called the macula. (acuvue.co.uk)
  • The macula is located roughly in the centre of the retina, temporal to the optic nerve. (geeyecare.com)
  • The greatest concentration of cones is found in the macula and fovea at the center of the retina. (bmrhc.net)
  • Macular degeneration (AMD) is an eye disease that affects the macula, the small central portion of your retina. (luxreaders.com)
  • It appears as small spots on the macula or elsewhere on the retina. (acudoctor.com)
  • The vitreous body and optic nerve head, as well as the retina, vessels and macula can also be examined with the slit lamp and another lens held in front of it. (proeyes.at)
  • Optical coherence tomography (OCT) is used to examine the optic nerve head, the retina (especially the macula), the cornea or the chamber angle. (proeyes.at)
  • The most sensitive part of the retina is a small area called the macula , which has millions of tightly packed photoreceptors (the type called cones). (msdmanuals.com)
  • Optical coherence tomography (OCT) of the right macula revealed detachment of the inner neurosensory retina with hyperreflective material in the subretinal space (Figure 2). (medscape.com)
Center of the retina2
  • The Macular Lutea is a small yellowish area lying slightly behind the center of the retina that constitutes the region of maximum visual acuity - called also yellow spot. (acudoctor.com)
  • At first, most of the increase in night vision comes from the cones, which are densely concentrated in the center of the retina. (telescope.com)
Controls the size of the pupil2
  • controls the size of the pupil. (puritan.com)
  • This circular muscle controls the size of the pupil so that more or less light, depending on conditions, is allowed to enter the eye. (utah.edu)
Iris and pupil3
Optic17
  • located at the back of the eye ball, the optic nerve sends visual information from the retina to the brain. (puritan.com)
  • Human eyes contain a small blind spot where the optic nerve connects to the retina. (puritan.com)
  • Rod and cone cells in your retina absorb the light and send messages to your brain via your optic nerve. (acuvue.co.uk)
  • The optic nerve carries impulses/messages from the retina to the brain where they are then interpreted as visual messages. (viteyes.com)
  • The retina converts the light into nerve impulses, which travel to the brain through the optic nerve. (vin.com)
  • Destruction of retinal pigment epithelium, migration of black pigment, extreme narrowing of retinal vessels, optic disc pallor. (xshotpix.com)
  • The optic disk is a spot on the retina where the tracks (fine nerves) from the photoreceptors all meet up to make the optic nerve. (eyevet.co.nz)
  • The optic nerve is essentially the cable of sensory nerves from the eyes retina / photoreceptors to the brain. (eyevet.co.nz)
  • When your Champaign, Illinois eye doctor is examining your eyes and talking about the cornea, pupil, optic nerve, and other parts, you may be wondering what these various parts are and the roles they play in helping you see. (champaigneyepro.com)
  • When images are picked up by your lens, they are sent to the retina, which then converts them into signals that are sent from the optic nerve to your brain. (champaigneyepro.com)
  • The optic nerve transmits electrical impulses from the retina to the brain. (geeyecare.com)
  • The retina's sensory receptor cells of the retina are absent from the optic nerve. (geeyecare.com)
  • The retina is the inner coating of the eye running from the edge of the iris back to the optic nerve. (bmrhc.net)
  • The receptor cells in the retina send nerve messages about what you see to the optic nerve. (bmrhc.net)
  • The increase in intraocular pressure accelerates the process of degeneration of the optic nerve and the retina. (happypetsnow.com)
  • The retina changes the light into electrical impulses, sends it to the brain, and receives an image through the optic nerve. (apollo247.com)
  • The photoreceptors in the retina convert the image into electrical signals, which are carried to the brain by the optic nerve. (msdmanuals.com)
Sclera6
  • Other life-forms such as horses, dogs, lizards etc often have a dark brown or black sclera. (rense.com)
  • The bluish-black sclera in his eyes is a rare disease called alkaptonuria. (rense.com)
  • However, the sclera does not turn pitch black with this disease. (rense.com)
  • Are there beings or people among us whose sclera, pupils and iris are completely BLACK? (rense.com)
  • This anterior portion is formed by the sclera (white part), iris (colored part), pupil (the black point), drainage channels and ciliary tissues. (happypetsnow.com)
  • The ocular tissue where these tumors arise, the uvea, is a densely pigmented layer that lies for the most part between the sclera and the retina. (medscape.com)
Human retina2
Photoreceptors in the retina1
  • Light entering the eye strikes three different photoreceptors in the retina: the familiar rods and cones used in image forming and the more newly discovered photosensitive ganglion cells. (papasindiagrill.com)
Focus light onto the retina5
Vitreous7
  • Anterior chamber (between cornea and iris), Posterior chamber (between iris, zonule fibers and lens) and the Vitreous chamber (between the lens and the retina). (utah.edu)
  • The lens is the transparent layerings of the eye and the vitreous humor is the space between the lens and retina. (ultimareplenisher.com)
  • The vitreous is a clear jelly like liquid that fills the majority of the back portion of the eye (from the back of the lens to the retina). (eyevet.co.nz)
  • In otherwise healthy eyes, they are caused by the natural structure of the vitreous gel inside the eye that casts shadows on the retina. (aao.org)
  • The vitreous is firmly attached to certain areas of the retina. (geeyecare.com)
  • Your inner eye or the space between the posterior chamber behind the lens and the retina is the vitreous body. (bmrhc.net)
  • The retinal whitening involved the outer retina and was without any associated vitreous opacities or inflammation. (medscape.com)
Cone cells3
  • That light is then received by the retina - tissue in the back of your eye that houses all of the rod and cone cells. (clevelandclinic.org)
  • Drusen is a waste product of the recycling of constituents of the light-sensing reactions that occur in the rod and cone cells of the retina. (acudoctor.com)
  • But when in the dark the concentration of these chemicals begins to grow and the rod cells and cone cells in the retina become more and more light sensitive. (telescope.com)
Fovea5
  • Some vertebrate retinas have instead of a fovea, another specialization of the central retina, known as an area centralis or a visual streak. (utah.edu)
  • These muscles, named extraocular muscles rotate the eyeball in the orbits and allow the image to be focussed at all times on the fovea of central retina. (utah.edu)
  • In fish eyes, this detriment can be corrected by having a pupil with different focal lengths- i.e., different sharpness in the way light is angled towards the fovea. (koryoswrites.com)
  • Alligators have a special adaptation in their eyes called a fovea, which is a small area of the retina that is densely packed with photoreceptor cells. (contactlensvision.com)
  • Humans have a higher concentration of cones, which are responsible for detailed vision and color perception, in the central part of the retina known as the fovea. (sacbulldogs.com)
Areas of the retina1
Retinal4
  • When the combined refractive power of the cornea and lens is too high for the length of the eye, the retinal image will be in focus in front of the retina and out of focus on the retina, yielding myopia. (wikipedia.org)
  • A similar poorly focused retinal image happens when the combined refractive power of the cornea and lens is too low for the length of the eye except that the focused image is behind the retina, yielding hyperopia. (wikipedia.org)
  • If you have a retinal disease, the treatment will depend on the type of the disease and will require additional investigation by a retina specialist. (clevelandclinic.org)
  • From Wikipedia, the free encyclopedia The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells. (xshotpix.com)
Neurosensory retina1
Sensitive part of the retina1
  • It is a small and highly sensitive part of the retina responsible for detailed central vision. (geeyecare.com)
Constrict3
Passes13
Dilate and contract2
  • The stroma connects to the muscles that allow the pupils to dilate and contract. (viteyes.com)
  • Thanks to the stroma connecting to a muscle, your pupils can dilate and contract. (champaigneyepro.com)
Dilates3
Vertical slit pupil2
Enters10
Central retina1
  • Humans have very high levels of cones compared to most animals (nearing 100% in the central retina compared to 20% cones in the dog). (eyevet.co.nz)
Cataracts2
  • Whereas cataracts are opaque and interfere with light transmission to the retina, lenticular sclerosis causes no functional visual impairment. (pethealthnetwork.com)
  • How can you know if your pet's graying pupils represent cataracts or lenticular sclerosis? (pethealthnetwork.com)
Nerves3
Muscles7
Dilation6
Rods and c1
Posterior3
  • In the posterior part and not visible is the cornea, the lens, the retina, which is the inner lining of the eye. (happypetsnow.com)
  • However, for a precise examination of the posterior segment of the eye, the eyes must first be instilled with pupil-dilating eye drops. (proeyes.at)
  • For this purpose, pupil-dilating eye drops need to be applied, as in the slit lamp examination of the "posterior segment" of the eye. (proeyes.at)
Centre2
Sensory3
Slit8
  • If you click for a larger view you can just barely make out the slit pupils. (koryoswrites.com)
  • Again, in all these groups, slit pupils evolved separately . (koryoswrites.com)
  • So what advantages do slit pupils confer? (koryoswrites.com)
  • Slit pupils are found most often in animals with eyes that are exposed to highly variable light conditions- i.e., nocturnal or crepuscular animals. (koryoswrites.com)
  • Slit pupils allow the iris to contract or expand more dramatically- a human's round pupil can expand to allow light to be 10-fold more intense compared to its smallest size, while a cat's pupil expands to 135-fold intensity. (koryoswrites.com)
  • Recently, a theory has been proposed that the slit pupil aids predatory animals in seeing color in different light conditions. (koryoswrites.com)
  • Let's now go back to the terrestrial eye and compare the constriction of a slit pupil with that of a round pupil. (koryoswrites.com)
  • Cats' retinas are very sensitive, and that narrow slit prevents too much light from shining on the retina during daylight hours. (catboxclassics.com)
Large Pupils2
  • So, you combine the need to hunt for food and the practice of doing so in low light and you have a recipe for large pupils. (catboxclassics.com)
  • As noted by Catster , large pupils can also indicate fear. (catboxclassics.com)
Membrane2
  • The retina is a special membrane along the inside of the eye that contains specialized cells called photoreceptors. (puritan.com)
  • Their third eyelid, tapetum lucidum, large cornea and pupil, unique retina, and clear membrane all work together to give the alligator excellent vision both on land and underwater. (contactlensvision.com)
Multi-layered1
  • The retina is a multi-layered structure covering the back surface of the eye housing rods, cones and blood vessels. (viteyes.com)
Cornea is the clear1
Size13
Focuses5
Outer3
  • Anatomically, the eye consists of three layers called the Tunica fibrosa (outer layer) , the Tunica vasculosa (mid layer), and the Tunica nervosa (retina) . (fountainmagazine.com)
  • High concentrations of rods at the outer portions of your retina act as motion detectors in your peripheral or side vision. (bmrhc.net)
  • Conditions in the outer retina are optimal for these effects because of the high concentrations of polyunsaturated fatty acids in the photoreceptor outer segment membranes. (acudoctor.com)
Nourishes1
Reflective layer2
  • This is a coloured reflective layer under the retina giving better night vision to those animals which possess them (not in man). (eyevet.co.nz)
  • This is a reflective layer behind the retina that helps to enhance the alligator's vision in low light conditions. (contactlensvision.com)
Ciliary1
  • The contraction or relaxation of these ligaments as a consequence of ciliary muscle actions, changes the shape of the lens, a process called accommodation that allows us to form a sharp image on the retina. (utah.edu)
Sight2
Eye's4
  • A colored circular muscle , the iris, which is beautifully pigmented giving us our eye's color (the central aperture of the iris is the pupil) (Fig. 1). (utah.edu)
  • Light rays reflected off objects first pass through the eye's translucent layer (the cornea), then into the black round part located in the front of the eye (pupillae, or pupil), and later go through the lenses. (fountainmagazine.com)
  • It has the extraordinary property of enhancing your eye's power of resolution to the point of microscopic precision-the pupil humbles any Hasselblad lens and develops your subsequent memories to National Geographic sharpness. (nybooks.com)
  • Behind an owl eye's rod-packed retina is another layer called the tapetum lucidum, which catches any light that may have passed through the retina and bounces it back to those sensitive rods. (abcbirds.org)
Cat's4
  • Under normal resting conditions, a cat's pupils appear to be narrow black slits. (catboxclassics.com)
  • So, expanding the pupil allows more light in and then cat's many rod photoreceptors are able to process that limited light in a way that best helps cats see in dim and dark conditions. (catboxclassics.com)
  • Whether your cat's afraid of a loud noise, a stranger coming through the front door or a large dog outside, their pupils will likely remain dilated until they make a determination about the potential threat. (catboxclassics.com)
  • So, if for some reason your cat's pupils suddenly get bigger for no apparent cause, you might want to speak softly to them and calm them down the best you can. (catboxclassics.com)
Floaters1
  • Spots or floaters in vision can look like grey or black specks, strings or cobwebs. (aao.org)
Blown pupil1
  • Mydriasis caused by traumatic brain injury is sometimes called a "blown pupil. (healthline.com)
Eyes10
  • Pupils are the black circles in your eyes. (healthline.com)
  • A common occurrence among children with black eyes is to ask permission to enter a vehicle or a home. (rense.com)
  • The eyes, specifically the retina, are able to take light and turn it into electrical signals, which the brain then uses to translate into the images that we are continuously seeing and what we perceive. (ultimareplenisher.com)
  • When you're in low or no light, your pupils (that black circle in the center of your eyes) will get bigger (dilate) so that more light will enter your eye. (clevelandclinic.org)
  • In bright conditions, the pupil shrinks or constricts to limit light entering into the eyes, so that too much light can't cause glare and discomfort to the eye, and even can't damage to the lens and retina of the eye. (tutorialspoint.com)
  • Children with light-colored eyes tend to have noticeably larger pupils. (aao.org)
  • In addition to their out-sized eyes, owl pupils dilate extremely wide to let as much light as possible hit the light-sensitive retina at the back of the eye. (abcbirds.org)
  • The area surrounding the eyes is white has black stripes and is separated from the beak by a featherless patch. (imparrot.com)
  • Alligators have a layer of cells in their eyes called tapetum lucidum, which reflects light back through the retina, giving them better vision in low light. (contactlensvision.com)
  • Less light gets into your eyes as your pupils shrink with age, and this affects the sharpness of your vision. (coxautoservice.net)
Tissue5
Macular2
Choroid2
Blood vessels1
Blindness3
  • Night Blindness (Nyctalopia) is a symptom of an underlying disease such as a retina problem. (clevelandclinic.org)
  • In pets with PRA, the retina degenerates over time, leading to blindness. (vin.com)
  • This syndrome is a disease in dogs in which the retina rapidly and irreversibly deteriorates, leading to blindness within days to months. (vin.com)
Circular4
Eyeball3
  • Farsightedness occurs if your eyeball is too short or the cornea has too little power, so light entering your eye is focused behind the retina, instead of directly on the retina, causing blurred vision. (ferris.edu)
  • Nearsightedness occurs if your eyeball is too long or the cornea is too powerful, so the light entering your eye is focused before the retina, instead of directly onto the retina, causing blurred vision. (ferris.edu)
  • The lens' job is to focus light rays onto the back of the eyeball (called the retina). (acudoctor.com)
Converts light2
  • Your retina converts light energy into a nerve impulse that is carried to the brain and then interpreted. (menstuff.org)
  • The retina is a 10-layered structure that converts light signals into nerve impulses that are sent to the brain for interpretation into an image. (vin.com)
Anisocoria2
Sharpness1
Widen2
  • Typically, the pupils dilate, or widen, in response to low light so they can collect more light. (healthline.com)
  • Cats' pupils do the same, except measurements indicate that their pupils can widen a lot more than ours. (catboxclassics.com)
Feline1
  • The diametrical opposite of a narrow-shaped feline pupil, wide-open pupils often indicate excitement or fear. (papasindiagrill.com)
Examine2
Back9
  • Structure at the back of the eye responsible for carrying nerve impulses from the retina to different areas of the brain. (ferris.edu)
  • A transparent gel located in the back 2/3 of the eye, filling in the area between the lens and the retina. (ferris.edu)
  • A light sensitive layer towards the back of the eye, the retina is responsible for converting light energy into signals that are carried to the brain where they are understood as shapes, movement and colors. (viteyes.com)
  • Essentially what the pupil does is allow light to pass through the eye and onto the retina at the back of the eye. (koryoswrites.com)
  • When prescribed medications cause it, the pupils will go back to normal after the effect diminishes and you stop taking the medication. (papasindiagrill.com)
  • The cornea not only protects the front of the eye, but also helps focus light on the retina at the back of the eye. (msdvetmanual.com)
  • It directs light rays into the eye and helps focus them on the light-sensitive retina at the back of the eye, providing sharp, clear vision. (luxreaders.com)
  • It is a detailed examination of the whole back of the eye and especially of the whole retina. (proeyes.at)
  • The cornea serves as a protective covering for the front of the eye and also helps focus light on the retina at the back of the eye. (msdmanuals.com)
Structures1
  • This permits a doctor or researcher to directly view the retina using off-axis (side view) imaging for diagnosing eye disease, without the limited viewing the retina through the lens and cornea structures of the eye. (rense.com)
Small6
  • A small area on the retina that is used for central, detailed vision. (ferris.edu)
  • The espresso at your cup's bottom is the only small black dot in, you feel, a miles-long radius. (nybooks.com)
  • Many nocturnal species have round pupils which are actually quite good at contracting to very small sizes. (koryoswrites.com)
  • Constricted, or small pupils, can occur for a variety of reasons including eye injuries, brain trauma, medication side effects and stroke. (papasindiagrill.com)
  • The process is pretty straight forward, except there is a small area on our retina is where there are no photoreceptors. (personalexcellence.co)
  • If optical aberrations in the eye could be eliminated, the theoretical limit of foveal acuity would be 20/12 for a small pupil and up to 20/5 for a dilated pupil. (medscape.com)
Nerve cells2
Photoreceptor cells1
Cells7
  • It occurs when the color-sensitive cells in the retina do not properly pick up or send the proper color signals to the brain. (ferris.edu)
  • (b) Name the cells on the retina of an eye which are sensitive to (i) bright light (ii) dim light (iii) sensation of colour. (tutorialspoint.com)
  • The retina of our eye contains a large number of light-sensitive cells that respond to light. (tutorialspoint.com)
  • At any rate, you obey the command and grab your camera, supplementing both your brain cells and pupils. (nybooks.com)
  • Where are the pigmented cells located in the retina? (xshotpix.com)
  • Older adults have fewer rod cells - light receptors in the retina responsible for the black-and-white vision that's essential for night driving. (coxautoservice.net)
  • When your eye is fully dark adapted, most of your night vision comes from the rod cells in the retina. (telescope.com)