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eye
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eye (i) the organ of vision.
black eye  a bruise of the tissue around the eye, marked by discoloration, swelling, and pain.
crossed eyes  esotropia.
exciting eye  the eye that is primarily injured and from which the influences start which involve the other eye in sympathetic ophthalmia.
Klieg eye  conjunctivitis, edema of the eyelids, lacrimation, and photophobia due to exposure to intense lights (Klieg lights).
wall eye 
1. leukoma of the cornea.

eye ()
n.
1. An organ of vision or of light sensitivity.
2. Either of a pair of hollow structures located in bony sockets of the skull, functioning together or independently, each having a lens capable of focusing incident light on an internal photosensitive retina from which nerve impulses are sent to the brain; the organ of vision.
3. The external, visible portion of this organ together with its associated structures, especially the eyelids, eyelashes, and eyebrows.
4. The pigmented iris of this organ.
5. The faculty of seeing; vision.
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eye
cross section

eye
Etymology: AS, eage
one of a pair of organs of sight, contained in a bony orbit at the front of the skull, with retrobulbar fat, and innervated by four cranial nerves: optic, oculomotor, trochlear, and abducens. Associated with the eye are certain accessory structures, such as the muscles, the fasciae, the eyebrow, the eyelids, the conjunctiva, and the lacrimal gland. The bulb of the eye is composed of segments of two spheres with nearly parallel axes that constitute the outside tunic and one of three fibrous layers enclosing two internal cavities separated by the crystalline lens. The smaller cavity anterior to the lens is divided by the iris into two chambers, both filled with aqueous humor. The posterior cavity is larger than the anterior cavity and contains the jellylike vitreous body that is divided by the hyaloid canal. The outside tunic of the bulb consists of the transparent cornea anteriorly, constituting one fifth of the tunic, and the opaque sclera posteriorly, constituting five sixths of the tunic. The intermediate vascular, pigmented tunic consists of the choroid, the ciliary body, and the iris. The internal tunic of nervous tissue is the retina. Light waves passing through the lens strike a layer of rods and cones in the retina, creating impulses that are transmitted by the optic nerve to the brain. The transverse and the anteroposterior diameters of the eye bulb are slightly greater than the vertical diameter; the bulb in women is usually smaller than the bulb in men. Eye movement is controlled by six muscles: the superior and inferior oblique muscles and the superior, inferior, medial, and lateral rectus muscles. Also called bulbus oculi, eyeball.

eye [i]
the organ of vision; see also Plates. In the embryo the eye develops as a direct extension of the brain, and thus is a very delicate organ. To protect the eye the bones of the skull are shaped so that an orbital cavity protects the dorsal aspect of each eyeball. In addition, the conjunctival sac covers the front of the eyeball and lines the upper and lower eyelids. Tears from the lacrimal duct constantly wash the eye to remove foreign objects, and the lids and eyelashes help protect the front of the eye.
Structure. The eyeball has three coats. The cornea is the clear transparent layer on the front of the eyeball; it is a continuation of the sclera (the white of the eye), the tough outer coat that helps protect the delicate mechanism of the eye. The choroid is the middle layer and contains blood vessels. The third layer, the retina, contains rods and cones, which are specialized cells that are sensitive to light. Behind the cornea and in front of the lens is the iris, the circular pigmented band around the pupil. The iris works much like the diaphragm in a camera, widening or narrowing the pupil to adjust to different light conditions.
Function. (See also vision.) The refraction or bending of light rays so that they focus on the retina and can thus be transmitted to the optic nerve is accomplished by three structures: the aqueous humor, a watery substance between the cornea and lens; the lens, a crystalline structure just behind the iris; and the vitreous humor, a jelly-like substance filling the space between the lens and the retina. Unlike the lens of a camera, the lens of the eye focuses by a process called accommodation. This means that when the eye sees something in the distance, muscles pull the lens, stretching it until it is thin and almost flat, so that the light rays are only slightly bent as they pass through it. When the object is close, the muscles relax and the elastic lens becomes thicker, bending the light rays and focusing them on the retina.ƒ

Because the eye must function under many different circumstances, there are two types of nerve cells in the retina, with different shapes: the cones and the rods. They cover the full range of adaptation to light, the cones being sensitive in bright light, and the rods in dim light. The cones are responsible for color vision. There are three types of cones, each containing a substance that reacts to light of a different color, one set for red, one for green, and one for violet. These are the primary colors in light, which, when mixed together, give white. White light stimulates all three sets of color cells; any other color stimulates one or two.

The optic nerve, which transmits the nerve impulses from the retina to the visual center of the brain, contains nerve fibers from the many nerve cells in the retina. The small spot where it leaves the retina does not have any light-sensitive cells, and is called the blind spot.

The eyes are situated in the front of the head in such a way that human beings have stereoscopic vision, the ability to judge distances. Because the eyes are set apart, each eye sees farther around an object on its own side than does the other. The brain superimposes the two slightly different images and judges distances from the composite image.
Disorders of the Eye. If the eyeball is too short or too long, the lens focuses the image not on the retina but behind or in front of it. The former condition is called hyperopia (or farsightedness) and the latter myopia (or nearsightedness). An irregularity in the curvature of the cornea or lens can cause the impaired vision of astigmatism. strabismus (or squint or crossed eyes) is usually caused by weakness in muscles that control movement of the eyeball. conjunctivitis is an inflammation of the membrane that covers the front of the eyeball and lines the eyelids. When small pieces of the retina become detached from the underlying layers, the result is a retinal detachment; surgery may be necessary to prevent blindness. presbyopia (usually taking the form of hyperopia) occurs in older persons and develops as the lens loses its elasticity with the passing years. Correction is easily made with properly prescribed eyeglasses.ƒ

Foreign bodies in the eyes are common occurrences. Protective eyewear should be worn by individuals at risk. Cinders, grit, or other foreign bodies are best removed by lifting the eyelid by the lashes. The foreign body will usually remain on the surface of the lid, and can easily be removed. Particles embedded in the eyeball must be removed by a qualified health care professional.

Eyestrain is fatigue of the eyes caused by improper use, uncorrected defects in the vision, or an eye disorder. Symptoms may include aching or pains in the eyes, or a hot, scratchy feeling in the eyelids. Headache, blurring or dimness of vision, and sometimes dizziness or nausea may also occur.
Anatomic features of the eye. From Ignatavicius and Workman, 2002.
artificial eye a glass or plastic prosthesis inserted in the eye socket to replace the eyeball; most are designed to be worn day and night. When patients become debilitated and unable to care for such a prosthesis, they must depend on members of the health care team to give proper care according to the chosen preferred routine.ƒ

Cleaning of a prosthetic eye is similar in principle to care of dentures; both are handled with care to avoid damage and are cleansed according to good hygienic principles. The prosthesis is removed while the patient is lying down so that it falls into the hand and is not likely to be dropped and broken. It is removed by depressing the lower eyelid, allowing the prosthesis to slide out and down. Mild soap and water are most often used for cleansing the prosthesis. Alcohol or other chemicals can damage prostheses made of plastic. If it is not replaced in the socket immediately after cleansing, it is stored in water or contact lens soaking solution. Insertion of the prosthesis is done by lifting the upper eyelid with the thumb or forefinger and placing its notched edge toward the nose. It is placed as far as possible under the upper lid and then the lower lid is depressed to allow it to slip into place. The process can be made easier by first moistening the prosthesis with water. If it is necessary to wipe the eye area of a patient wearing a prosthesis, one should gently wipe toward the nose in order not to dislodge the prosthesis.
cross eye esotropia.
pink eye popular term for acute contagious conjunctivitis.
raccoon e's ecchymotic areas surrounding both eyes, suggestive of a basilar skull fracture.
wall eye exotropia.

eye,
n one of a pair of organs of sight, contained in a bony orbit at the front of the skull.
eye, assessment of,
n an examination of the eyes–which includes an observation of pupil size, sclera color, the relative location of the eyeball, and use of corrective eyeware–to determine the presence of disease.
eye-ear plane,

eye
the organ of vision. In the embryo the eye develops as a direct extension of the brain, and thus is a very delicate organ. To protect the eye the bones of the skull are shaped so that an orbital cavity protects the dorsal aspect of each eyeball. In addition, the conjunctival sac covers the front of the eyeball and lines the upper and lower eyelids. Tears from the lacrimal duct constantly wash the eye to remove foreign objects, and the lids and eyelashes aid in protecting the front of the eye.
The eyeball has three coats. The cornea is the clear transparent layer on the front of the eyeball. It is a continuation of the sclera (the white of the eye), the tough outer coat that helps protect the delicate mechanism of the eye. The choroid is the middle layer and contains blood vessels. The third layer, the retina, contains rods and cones, which are specialized cells that are sensitive to light. Behind the cornea and in front of the lens is the iris, the circular pigmented band around the pupil. The iris works much like the diaphragm in a camera, widening or narrowing the pupil to adjust to different light conditions.
The optic nerve, which transmits the nerve impulses from the retina to the visual center of the brain, contains nerve fibers from the many nerve cells in the retina. The small spot where it leaves the retina does not have any light-sensitive cells, and is called the blind spot.

eye adnexa
include orbital fascia, ocular muscles, eyelids, tunica conjunctiva, lacrimal apparatus and, in the pig, the orbital ligament.
almond-shaped eye
observed with dehydration in birds, where the eyeball is sunken, particularly in raptors which normally have a prominent, round globe.
blue eye
a common term for corneal edema. See also blue eye.
cancer eye
common lay term for ocular squamous cell carcinoma.
cherry eye
china eye
one with a blue iris.
cross eye
esotropia.
diamond-shaped eye
seen in dogs with sunken eyes and loose skin in the eyelids which drop inwards, such as St. Bernards and Newfoundland. Often contributes to entropion.
eye drop
vestibular nerve lesion will cause the eye on the affected side to deviate downward more than the opposite eye when the head is lifted.
dry eye
fatty eye
permanent protrusion of the lower conjunctival sac; thought to be inherited in some breeds of guinea pigs.
mirror eye
term for congenital cataracts in guinea pigs.
pink eye
pinkeye.
eye preservation reflex
red eye
an eye showing dilation of conjunctival, episcleral or ciliary blood vessels.
eye reflexes
includes eye preservation (menace), pupillary light, consensual light reflexes.
eye specialist
eye teeth
see canine teeth.
wall eye, walleye
the irregular distribution of melanin in a blue iris. Seen commonly in dogs with merle coat color and Siberian huskies. Called also heterochromia iridis. In humans, the term refers to exotropia, or divergent strabismus. See also walleye.
eye wash
various medicated solutions used to flush the eye; called also collyria.
watch eye
one with an iris containing blue and yellow or brown pigment.
eye white percentage
an estimate of the startle response and an indicator of fear in dairy cattle.
white eye syndrome
congenital cataract associated with congenital bluetongue infection in calves.
eye worm

eye
The peripheral organ of vision, in which an optical image of the external world is produced and transformed into nerve impulses. It is a spheroidal body approximately 24 mm in diameter with the segment of a smaller sphere (of about 8 mm radius), the cornea, in front. It consists of an external coat of fibrous tissue, the sclera and transparent cornea; a middle vascular coat, comprising the iris, the ciliary body and the choroid; and an internal coat, the retina, which includes the cones and rods photoreceptors. Within the eye, there are the aqueous humour located between the cornea and the crystalline lens, the crystalline lens held by the zonule of Zinn and the vitreous body located between the crystalline lens and the retina. The movements of the eye are directed by six extraocular muscles (Fig. E9). Syn. organ of sight; visual organ.
amaurotic eye See amaurosis.
amblyopic eye An eye which has amblyopia. Syn. lazy eye (colloquial).
aphakic eye An eye without the crystalline lens.
artificial eye A prosthesis made of glass or plastic which resembles the eye and which is placed in the socket after enucleation. See ocularist; ocular prosthesis.
axial length of the eye See axial length of the eye.
eye bank An organization that collects, evaluates, stores and distributes eyes from donors. The eyes are used for corneal transplants and research. See keratoplasty.
black eye A colloquial term for a swollen or blue-black spot on the skin of the eyelid caused by effusion of blood as a result of a superficial injury in which the skin is not broken. The correct term is ecchymosis of the eyelid. The condition recovers by itself within 2-3 weeks while changing in colour to yellow. Immediately after the injury, application of ice helps minimize the haemorrhage and swelling. See haematoma.
bleary eye A red and watery eye, with a lacklustre appearance. Lack of sleep is a common cause. Syn. blear eye.e. blink See blink.
compound eye The eye of arthropods composed of a variable number of ommatidia. See corneal facet; ommatidium.
crossed eye's See convergent strabismus.
cyclopean eye Imaginary eye located at a point midway between the two eyes. When the two visual fields overlap and the impressions from the two eyes are combined into a single impression, the apparent direction of a fixated object appears in a direction that emanates from the cyclopean eye.
dark-adapted eye An eye that has been in darkness and is sensitive to low illumination. Syn. scotopic eye.
deviating eye The non-fixating eye in strabismus or under heterophoria testing. Syn. squinting eye.
dominant eye The eye that is dominant when ocular dominance exists. See manoptoscope; hole in the card test.
dry eye This term encompasses various tear film disorders ranging from a mild form causing discomfort, which is usually relieved with artificial tears, to the most common form keratoconjunctivitis sicca. See keratoconjunctivitis sicca.
equatorial plane of the eye See equatorial plane.
exciting eye See sympathetic ophthalmia.
fixating eye The eye that is directed towards the object of regard in strabismus. See deviating eye.
glass eye An artificial eye made of glass. See ocularist; ocular prosthesis.
eye impression See eye impression.
lazy eye See amblyopic eye.
eye lens See eyepiece.
light-adapted eye An eye that has been exposed to light and is insensitive to low illumination. Syn. photopic eye. See light adaptation; duplicity theory.
eye movements See eye movements.
eye patch A piece of material or plastic that is worn over the eye when it has been injured or over the socket when it is missing.
phakic eye An eye that contains the crystalline lens. See phakic.
photopic eye See light-adapted eye.
pink eye See contagious conjunctivitis.
eye position Position of the eye in the orbit, maintained by the extraocular muscles. See primary position; secondary position; tertiary position.
pseudophakic eye An eye fitted with an intraocular lens implant. See intraocular lens.
red eye A colloquial term often used for any condition in which the blood vessels of the conjunctiva or ciliary body are congested. Many conditions result in a red eye (e.g. subconjunctival haemorrhage, pterygium, conjunctivitis, episcleritis, corneal abrasion, corneal erosion, ulcerative keratitis, corneal dendritic ulcer, acute iritis, angle-closure glaucoma, orbital cellulitis, and possibly contact lens wear). See ciliary injection; con-junctival injection.
reduced eye A mathematical model of the optical system of the eye. It consists of a single refracting surface with one nodal point, one principal point and one index of refraction. In the first such model, proposed by Listing in 1853, the refracting surface had a power of 68.3 D and was situated 2.34 mm behind the schematic eye's cornea. It had an index of refraction of 1.35, a radius of curvature of 5.124 mm and a length of 20 mm. Donders' reduced eye was even more simplified. It has a power of 66.7 D, a radius of curvature of 5 mm, an index of refraction of 4/3 and anterior and posterior focal lengths of −15 and +20 mm, respectively, with a refracting surface situated 2 mm behind the schematic eye's cornea. Gullstrand's reduced eye has a radius of curvature of 5.7 mm, an index of refraction of 1.33, a power of 61 D with the refracting surface situated 1.35 mm behind the schematic eye's cornea. Emsley's reduced eye has a power of 60 D, an index of refraction of 4/3 and is situated 1.66 mm behind the schematic eye's cornea, with anterior and posterior focal lengths of −16.67 and +22.22 mm, respectively.
schematic eye A model consisting of various spherical surfaces representing the optical system of a normal eye based on the average dimensions (called the constants of the eye) of the human eye. There are many schematic eyes, although the most commonly used is that of Gullstrand. A great deal of variation among authors stemmed from the difficulty in giving an index of refraction that would represent the heterogeneous character of the crystalline lens. Gullstrand in fact proposed two schematic eyes, one which he called the exact schematic eye and the other which he called the simplified schematic eye in which the divergent effect of the posterior corneal surface is ignored and the cornea replaced by an equivalent surface; the crystalline lens is homogeneous and the optical system is free from aberrations.
scotopic eye See dark-adapted eye.
eye shield 1. See occluder.
2. A protective device to cover the eye against injury, glare or in radiotherapy of the face.
sighting-dominant eye The eye that is preferred in monocular tasks, such as looking through a telescope or aiming a firearm.
eye socket The bony orbit which contains the eyeball, the muscles, the nerves, the vessels, the orbital fat and the orbital portion of the lacrimal gland.
eye speculum An instrument designed to hold the eyelids apart during surgery. Syn. blepharostat.
squinting eye See deviating eye.
eye stone A small, smooth shell or other object that can be inserted beneath the eyelid to facilitate the removal of a foreign body from the eye.
sympathetic eye The uninjured eye in sympathetic ophthalmia that becomes secondarily affected. Syn. sympathizing eye.
wall eye A colloquial term referring to (1) a white opaque cornea or (2) a divergent strabismus.
watery eye See epiphora.
Fig. E9 Cross-section of the eyeenlarge picture
Fig. E9 Cross-section of the eye

Patient discussion about eye.

Q. What can you do to make your eye sight better? My eye sight isn’t that great. Is there anyway to improve it, like eating certain foods or drinking certain drinks?

A. Carrots
Very rich in Vitamin A. "Carrots are good for your eyesight", we were told as children and indeed around 500, 000 children worldwide are going blind every year because their diet and their mothers' breast milk does not contain sufficient amounts of vitamin A and Beta-carotene.
Beta carotene is a substance that is converted to Vitamin A in the human body. This vitamin helps transfer fat to energy. A 1/2 cup serving of cooked carrots contains four times the recommended daily intake of Vitamin A. Beta-carotene is also a powerful antioxidant effective in fighting against some forms of cancer.

For the entire list you can go to:
http://www.eyerobics.com.au/eyesight_food.html

Q. Should I have eye laser surgery? I am 17 and have been wearing glasses since I was a kid. I was thinking of having an eye laser surgery in order to fix my eyesight. What are the risks?

A. i had the surgery done almost a year and a half ago, i love it,the risk is minamal,do it,u won"t regret it,i now have 20/15 vision, and i was blind as a bat before,20/15 is over perfect vision!!!!!!!!!!!!

Q. Is it common to get an allergic reaction in the eye from olive harvest? I've been around olive trees for a few hours and now feel like I have something in my eye but there is nothing there. can it be an allergic reaction? I dont get it from eating olives...

A. but in one eye..? that just doesn't seem likely. but i guess there is no reason not to try both treatments....

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Why We Get Eye Bags Some people are, unfortunately, genetically predisposed to getting eye bags.
Getting on stage and just hitting a move or getting eye contact or feeling a moment, you can feel from the audience if youÕre doing it right.
Why We Get Eye Bags Some people are, unfortunately, genetically predisposed to getting eye bags.
 
 
 
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