Pink Eye


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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.
Acute contagious conjunctivitis caused by Haemophilus aegyptius or H ducreyi

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
References in periodicals archive ?
Although I think it the sunburnt eyelids were a dead giveawaynot to mention causing me to look like a drag queen with a penchant for bright pink eye shadow.
The trend, supposedly a dating practice that's now considered the next "base" after kissing, has even led to a Pink Eye epidemic in high schools.
So dig out two very different sides of the palette - pair a pastel pink eye with a red lip; a pink flushed cheek with a dark red shadow, and mix it up with the newest products on counter.
The term pink eye usually suggests an unpleasant eye infection but in the fashion world pink eye is all the rage with celebrities from Emma Stone to Whitney Port applying soft baby pink shades to their eye lids.
Buy a three-plant collection - one each of the light pink with deep pink eye Bright Eyes, the vibrant red Starfire and rose pink Eva Cullum - for just pounds 5.
Pink eye colour can be worn with the brightest blue mascara or keep it monochrome for a no-excess, no fuss look that is pure drama.
Rabbani, Los Angeles pink eye doctor, treats patients of all ages and provides specialty services for contact lenses, ocular disease treatment and laser vision correction.
Washington, April 16 (ANI): Researchers have been able to determine the part of viral keratoconjunctivitis which causes pink eye, making it possible to come up with a remedy for the problem in future.
Center Kostas Charissis has suffered pink eye this week.
Bacterial conjunctivitis - This is a highly contagious form of pink eye caused by bacterial infections, such as Staphylococcus or Streptococcus.
He's got pink eye, and I told him that when I see him, he's gonna have a purple eye," Contactmusic quoted Marlon as saying.