dry eye

dry eye

n.

Keratoconjunctivitis characterized by decreased tear flow and thickening and hardening of the cornea and conjunctiva. Also called dry-eye syndrome, keratoconjunctivitis sicca.

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dry

a state of dehydration or relative deficiency of water.

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dry bench

1. that part of a radiographic dark room where film and cassettes are handled, i.e. there is no chance of film being contaminated by chemicals.

2. a slang expression for simulated research work, for reported experiments that were not actually done.

dry coat syndrome

see anhidrosis.

dry eye

see keratoconjunctivitis sicca.

dry feeding

the entire ration is made up of dried stored grain or hay.

dry food

the meal or biscuit type dog and cat foods that contain approximately 10% water. Economical, easily transported and stored; in many countries, this is the most commonly used form of mass produced pet food.

dry ice

solidified carbon dioxide; in an icebox, it produces temperatures of about −76°F (−60°C).

dry lot

the livestock, usually cattle, are kept in a small area with a firm floor but no roof or walls. All food and water are brought to them. Refers usually to dairy herds. See also feedlot.

dry mash

a method of feeding poultry. Essentially a mixture of grain and supplements.

dry rales

see rale.

dry sow

pregnant sow.

dry sow house/room

area where sows are housed and fed between mating and farrowing. Called also gestation barn.

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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.

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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

see 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

see keratoconjunctivitis sicca.

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

see menace 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

see ophthalmologist.

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

see thelazia, onchocerca.

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Patient discussion about dry eye.

Q. What Causes Dry Eyes? I have been suffering from eye dryness lately, what causes this situation?

A. Dry eyes are often caused when the lacrimal gland does not produce sufficient tears to keep the entire conjunctiva and cornea, that are normally covered by a complete layer of tear film. This usually occurs in people who are otherwise healthy. Increased age is associated with decreased tearing. if it causes you real discomfort talk to a doctor.