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  • retinal
  • Retinal detachment is a separation of the light-sensitive membrane (retina) in the back of the eye from its supporting layers. (medlineplus.gov)
  • The most common type of retinal detachment is often due to a tear or hole in the retina. (medlineplus.gov)
  • Lasers may be used to seal tears or holes in the retina before a retinal detachment occurs. (medlineplus.gov)
  • Visual acuity is dependent on optical and neural factors, i.e., (i) the sharpness of the retinal focus within the eye, (ii) the health and functioning of the retina, and (iii) the sensitivity of the interpretative faculty of the brain. (wikipedia.org)
  • Recently, emerging retinal imaging modalities such as optical coherence tomography are capable of producing digital images of the retina with a micrometer resolution, which can be transmitted for research or diagnostic purposes. (wikipedia.org)
  • The innermost is the retina, which gets its oxygenation from the blood vessels of the choroid (posteriorly) as well as the retinal vessels (anteriorly). (wikipedia.org)
  • The clinical macula is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. (wikipedia.org)
  • A pop or click noise emanating from the eyeball may be the only indication that retinal damage has occurred i.e. the retina was heated to over 100 °C resulting in localized explosive boiling accompanied by the immediate creation of a permanent blind spot. (wikipedia.org)
  • Choroid
  • The main cause of the red color is the ample amount of blood in the choroid which nourishes the back of the eye and is located behind the retina. (wikipedia.org)
  • iris
  • Lacerations can occur in the inner structures of the eye, such as the retina, pupil, and iris. (canadavet.com)
  • The iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. (wikipedia.org)
  • The stroma connects to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. (wikipedia.org)
  • The high pigment content blocks light from passing through the iris to the retina, restricting it to the pupil. (wikipedia.org)
  • The iris is divided into two major regions: The pupillary zone is the inner region whose edge forms the boundary of the pupil. (wikipedia.org)
  • Continuous with the retina are the ciliary epithelium and the posterior epithelium of the iris. (wikipedia.org)
  • The iris is the pigmented circular structure concentrically surrounding the center of the eye, the pupil, which appears to be black. (wikipedia.org)
  • The size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris' dilator and sphincter muscles. (wikipedia.org)
  • When viewed at large angles from the side, the iris and pupil may still be visible by the viewer, indicating the person has peripheral vision possible at that angle. (wikipedia.org)
  • As soon as the eye moves rapidly to acquire a target (saccades), it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil. (wikipedia.org)
  • The eye is made up of the sclera, the iris, and the pupil, a black hole located at the center of the eye with the main function of allowing light to pass to the retina. (wikipedia.org)
  • Tadpole pupil, also known as episodic segmental iris mydriasis, is an ocular condition where the muscles of the iris begin to spasm causing the elongation, or lengthening, of parts of the iris. (wikipedia.org)
  • Contractions of the iris dilator muscle, a smooth muscle of the eye running radially in the iris, can cause irregular distortion of the pupil, thus making the pupil look tadpole shaped and giving this condition its name. (wikipedia.org)
  • Episodic segmental iris mydriasis was first described and termed "tadpole pupil" in 1912 by HS Thompson The primary symptom is pupillary distortion (changing of the size or shape of the pupil). (wikipedia.org)
  • cones
  • However, rescued cones respond to short but not longer wavelength light because TRβ2 under moderate hormonal stimulation normally induces M opsin and controls the patterning of M and S opsins over the retina. (jneurosci.org)
  • We found that type 3 deiodinase is expressed in the immature retina and that Dio3 −/− mice lose cones by neonatal cell death. (jneurosci.org)
  • Photons of light falling on the light-sensitive cells of the retina (photoreceptor cones and rods) are converted into electrical signals that are transmitted to the brain by the optic nerve and interpreted as sight and vision. (wikipedia.org)
  • ciliary
  • It requires not only the muscles of the eye - the muscles of orbit and the ciliary muscles - to be able to focus on a particular object through contraction and relaxation, but other parts of the retina such as the fovea to project a clear image on the retina. (wikipedia.org)
  • abnormal
  • The most common and obvious sign of retinoblastoma is an abnormal appearance of the retina as viewed through the pupil, the medical term for which is leukocoria, also known as amaurotic cat's eye reflex. (wikipedia.org)
  • fovea
  • However, images still appear unclear at two months due to other components of the visual system like the fovea and retina and the brain circuitry that are still in their developmental stages. (wikipedia.org)
  • dilate
  • Many fish have neither, and, as a result, their irides are unable to dilate and contract, so that the pupil always remains of a fixed size. (wikipedia.org)
  • Phenylephrine is a selective α1-adrenergic receptor agonist of the phenethylamine class used primarily as a decongestant, as an agent to dilate the pupil, and to increase blood pressure. (wikipedia.org)
  • Phenylephrine is used as an eye drop to dilate the pupil to facilitate visualization of the retina. (wikipedia.org)
  • exam
  • Depending on the position of the tumors, they may be visible during a simple eye exam using an ophthalmoscope to look through the pupil. (wikipedia.org)
  • Dilated Pupillary Exam: special drops expand the pupil, which then allows doctors to examine the retina. (wikipedia.org)
  • acuity
  • Neural factors that limit acuity are located in the retina or the brain (or the pathway leading there). (wikipedia.org)
  • The precise distance at which acuity is measured is not important as long as it is sufficiently far away and the size of the optotype on the retina is the same. (wikipedia.org)
  • outer
  • In most cases, the rods are affected first since they are in the outer portion of the retina and are easily triggered by things such as dimmed light. (eyehealthweb.com)
  • Symptoms
  • Some patients who demonstrate tadpole pupil symptoms also experienced Horner's syndrome or Adie's tonic pupil Tadpole pupil symptoms occur in episodes. (wikipedia.org)
  • Although women generally have the tadpole pupil, men are not unaffected by this disease and some have been reported to experience the symptoms. (wikipedia.org)
  • muscles
  • The two obliques prevent the eye from rotating about its long axis (retina to pupil) when the superior and inferior rectus muscles contract. (wikipedia.org)
  • The examinations can determine if any of the muscles of the eye or retina, which is linked to the pupil, have any problems that could relate to the tadpole pupil condition. (wikipedia.org)
  • epithelium
  • Most of the light is absorbed by melanin pigments in the pigment epithelium just behind the photoreceptors, and causes burns in the retina. (wikipedia.org)
  • enters the eye
  • A laser beam can be focused to an intensity on the retina which may be up to 200,000 times higher than at the point where the laser beam enters the eye. (wikipedia.org)
  • Photographs
  • The red-eye effect in photography is the common appearance of red pupils in color photographs of the eyes of humans and several other animals. (wikipedia.org)
  • Photographs taken with infrared light through night vision devices always show very bright pupils because, in the dark, the pupils are fully dilated and the infrared light is not absorbed by any ocular pigment. (wikipedia.org)
  • Red-eye effect is seen in photographs of children also because children's eyes have more rapid dark adaption: in low light a child's pupils enlarge sooner, and an enlarged pupil accentuates the red-eye effect. (wikipedia.org)
  • Similar effects, some related to red-eye effect, are of several kinds: In many flash photographs, even those without perceptible red-eye effect, the tapetum lucidum of many animals' pupils creates an "eyeshine" effect. (wikipedia.org)
  • In photographs recorded with infrared-sensitive passive (non-IR emitting) equipment, the eyes (not only the pupils) usually appear very bright. (wikipedia.org)
  • reflex
  • Given that drug poisoning is the cause for a large portion of patients in a coma, hospitals first test all comatose patients by observing pupil size and eye movement, through the vestibular-ocular reflex. (wikipedia.org)
  • Bright
  • Spotted eagle-owl displays red-eye effect only on the eye facing the camera's ring flash Canon EOS 100 camera with bright light to contract pupils Motorola Milestone XT720 camera while capturing image with red-eye reduction and xenon flash. (wikipedia.org)
  • circular
  • Due to certain muscle spasms in the eye, the pupil can resemble a tadpole, which consists of a circular body, no arms or legs, and a tail. (wikipedia.org)
  • test
  • Optical coherence tomography: This test uses light to produce a 2-dimensional cross-sectional picture of the retina. (clinicaltrials.gov)
  • In this test, light waves are used to make detailed images of the retina. (ahealthyme.com)
  • These tests include pharmacological testing (testing for an effective drug against a specific disease or condition), a complete ocular examination (a test that examines the entire eye), and video pupillography (recording and analysis of spontaneous pupil behavior in darkness). (wikipedia.org)
  • A test for Horner Syndrome is highly recommended to all the patients who have a history of tadpole pupil episodes because studies have linked the two conditions. (wikipedia.org)
  • display
  • Most users of a rMBP will be happy with the native Retina display resolution of 2,880 x 1,800, but more demanding (or adventurous) users may wish to regularly change their Mac's screen resolution to take advantage of the greater screen real estate rMBPs have to offer. (engadget.com)
  • becomes
  • If, however, one of your pet's pupils suddenly becomes larger or smaller than the other, it may be experiencing serious difficulties. (canadavet.com)
  • Even people with advanced retinopathy have a good chance of keeping their vision if they seek treatment before the retina becomes severely damaged. (ahealthyme.com)
  • visual system
  • Neuro-Ophthalmology is a peer-reviewed medical journal that covers diagnostic methods in neuro-ophthalmology such as visual fields, CT scanning and electrophysiology, the visual system such as the retina, oculomotor system, pupil, neuro-ophthalmic aspects of the orbit, and related fields such as migraine and ocular manifestations of neurological diseases. (wikipedia.org)
  • causes
  • This causes the retina to separate from the underlying tissues, much like a bubble under wallpaper. (medlineplus.gov)
  • Infrared light mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths. (wikipedia.org)
  • sensitivity to li
  • Wearing sunglasses indoors can make symptoms worse over time as it will dark-adapt the retina which aggravates sensitivity to light. (wikipedia.org)
  • Burning of the eye Redness of the eye Blurred vision Photophobia or sensitivity to light Irregular pupil Blacked out sclera Floaters, which are dark spots that float in the visual field Headaches Signs of anterior uveitis include dilated ciliary vessels, presence of cells and flare in the anterior chamber, and keratic precipitates ("KP") on the posterior surface of the cornea. (wikipedia.org)
  • photoreceptor
  • In his Colliget, Averroes (1126-1198) was the first to attribute photoreceptor properties to the retina, and he was also the first to suggest that the principal organ of sight might be the arachnoid membrane (aranea). (wikipedia.org)
  • Photons of light falling on the light-sensitive cells of the retina (photoreceptor cones and rods) are converted into electrical signals that are transmitted to the brain by the optic nerve and interpreted as sight and vision. (wikipedia.org)
  • Luminance
  • It is meant as a method for correcting photometric measurements of luminance values impinging on the human eye by scaling them by the effective pupil size. (wikipedia.org)
  • The troland typically refers to the ordinary or photopic troland, which is defined in terms of the photopic luminance: T = L × p {\displaystyle \mathrm {T} =\mathrm {L} \times \mathrm {p} } , where L is the photopic luminance in cd m−2 and p is pupil area in mm2. (wikipedia.org)
  • A scotopic troland is also sometimes defined: T ′ = L ′ × p {\displaystyle \mathrm {T'} =\mathrm {L'} \times \mathrm {p} } , where L′ is the scotopic luminance in cd m−2 and p is pupil area in mm2. (wikipedia.org)
  • Irregular
  • Contractions of the iris dilator muscle, a smooth muscle of the eye running radially in the iris, can cause irregular distortion of the pupil, thus making the pupil look tadpole shaped and giving this condition its name. (wikipedia.org)
  • atropine
  • the retina buy zolpiem online legally from canada is unprotected from bright light andthis often gives rise to pain and discomfort in the eyes and headache.besides the dilatation of the pupil, a further result of the applica-tion of atropine to the eye is the paralysis of the accommodation. (flippersmack.com)
  • aberrations
  • Based on a simple eye model system, a high resolution adaptive optics retina imaging system was built to demonstrate the availability of using liquid crystal devices as a wave-front corrector for both low and high order aberrations. (osapublishing.org)
  • acute
  • About 10% of people with closed angles present with acute angle closure characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure (>30 mmHg), nausea and vomiting, suddenly decreased vision, and a fixed, mid-dilated pupil. (wikipedia.org)
  • diameter
  • We can get a root mean square(RMS) correction precision of lower than 0.049λ (λ =0.63μm) for over to 10 diopters and the modulation transfer function (MTF) retains 51lp/mm, which is nearly the diffraction limited resolution for a 2.7mm pupil diameter. (osapublishing.org)
  • rods
  • Retinitis pigmentosa is a form of hereditary blindness where the rods and cones are destroyed, but the rest of the eye and retina remains intact. (bio-medicine.org)
  • With that model, you can't be sure what percentage of the rods and cones are gone, and you can't be sure that the degenerated retina itself isn't affecting your observations. (innovations-report.com)
  • The retina is dominated by rod cells, 1,000,000 rods per mm2, the highest density of any vertebrate eye, which are organised in layers, an arrangement unique among birds but shared by deep-sea fish. (wikipedia.org)
  • Glaucoma
  • Muslim physicians described such conditions as pannus, glaucoma (described as 'headache of the pupil'), phlyctenulae, and operations on the conjunctiva. (wikipedia.org)
  • Excessive
  • Overstimulation of the photoreceptors in the retina Excessive electric impulses to the optic nerve Excessive response in the central nervous system Elevated trigeminal nerve tone (as it is sensory nerve to eye, elevated tone makes it over reactive). (wikipedia.org)
  • muscles
  • The examinations can determine if any of the muscles of the eye or retina, which is linked to the pupil, have any problems that could relate to the tadpole pupil condition. (wikipedia.org)
  • consists
  • A functional assessment consists of the capability to relocate the orbit and the response of the pupil to light and lodging. (mybjjblog.com)
  • Due to certain muscle spasms in the eye, the pupil can resemble a tadpole, which consists of a circular body, no arms or legs, and a tail. (wikipedia.org)
  • nausea
  • The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. (wikipedia.org)
  • cells
  • The long blue strands are the cells axons, which head into the optic nerve and eventually end in parts of the brain that control the internal clock and the opening and closing of the pupil. (innovations-report.com)
  • apparent
  • Studies show that a majority of those experiencing tadpole pupil are younger women from an age range of 24 to 48 years old, with no apparent health problems. (wikipedia.org)
  • size
  • In any human age group there is however considerable variation in maximal pupil size. (wikipedia.org)
  • After 25 years of age the average pupil size decreases, though not at a steady rate. (wikipedia.org)
  • The reverse is true, so control of pupil size is controlled by differences in contraction intensity of each muscle. (wikipedia.org)
  • sight
  • 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)
  • black
  • It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil. (wikipedia.org)
  • known
  • At this stage the pupils do not remain completely still, therefore may lead to oscillation, which may intensify and become known as hippus. (wikipedia.org)
  • response
  • A functional evaluation includes the capability to move in the orbit and the response of the pupil to light and accommodation. (uzblog.net)
  • Experiments at Johns Hopkins with Robert Lucas from Imperial College London showed that the triple knockouts couldn't adjust their pupils at all in response to light. (innovations-report.com)
  • dark
  • The pupil gets wider in the dark and narrower in light. (wikipedia.org)
  • In the dark it will be the same at first, but will approach the maximum distance for a wide pupil 3 to 8 mm. (wikipedia.org)
  • For example, at the peak age of 15, the dark-adapted pupil can vary from 4 mm to 9 mm with different individuals. (wikipedia.org)
  • condition
  • When the pupil takes on the shape of a tadpole, the condition is called tadpole pupil. (wikipedia.org)
  • These tests include pharmacological testing (testing for an effective drug against a specific disease or condition), a complete ocular examination (a test that examines the entire eye), and video pupillography (recording and analysis of spontaneous pupil behavior in darkness). (wikipedia.org)
  • General
  • Some precautions include regular visits to an ophthalmologist or optometrist and general testing of the pupil and internal eye through fundamental examinations (listed below). (wikipedia.org)
  • less
  • As a result of this nodal point separation, images of objects move more or less on the retina based on their distance from the chameleon. (wikipedia.org)
  • among
  • Since LASIK eye surgical treatment involves the operation of the retina, which is among the most delicate portions of the eye, many people say that the operation can be really risky. (uzblog.net)
  • Since LASIK eye surgery includes the operation of the retina, which is among the most sensitive portions of the eye, many people say that the operation can be extremely dangerous. (blogolize.com)
  • structure
  • On the inner edge lies a prominent structure, the collarette, marking the junction of the embryonic pupillary membrane covering the embryonic pupil. (wikipedia.org)