Facts on File Encyclopedia of Health and Medicine

vocal cord nodule A noncancerous, fibrous growth on the vocal cord, usually the result of overusing the voice through repeated s ...

Singing and extended talking can greatly strain the vocal cords, resulting in inflammation (LARYN- GITIS) that causes the voice ...

Structures of the Eye EYELIDS IRIS LACRIMAL(TEAR) GLANDS PUPIL CONJUNCTIVA ANTERIOR CHAMBER SCLERA AQUEOUS HUMOR CORNEA LENS CHO ...

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provides depth perception and accommodates each eye’s “blind spot.” Some people have the ability to intentionally move their eye ...

produce aqueous humor. This watery fluid is about the consistency of saliva and serves also to lubricate and nourish the cornea. ...

The Eyes 69 line of vision. The lens remained within the eye as though resting, hence the term “couching.” The result was less t ...

A age-related macular degeneration (ARMD) A progressive condition that results in the gradual deterioration of the macula, the p ...

ARMD. Some research studies demonstrate the rate of degeneration slows with increased con- sumption of the antioxidants lutein a ...

fiers for reading and close work, adjustments on televisions and computers to enlarge screen images, voice-activated telephone d ...

treatment may result in permanent dysfunction of the eye–brain pathways, as these become entrenched by age 9 or 10. After this t ...

B black eye Bleeding into the tissues around the EYEresulting from trauma to the area, such as a blow or surgical OPERATION. As ...

blepharoplasty A surgical OPERATIONto remove excess tissue from the eyelids to correct drooping upper eyelids and “baggy” lower ...

Learning each variation of braille code is like learning a different language. Most people learn the one or two variations they ...

C cataract Cloudiness and discoloration of the LENS. Cataracts become increasingly common with advancing age, affecting half of ...

Gradual loss of vision at middle age and beyond may be a symptom of AGE- RELATED MACULAR DEGENERATION(ARMD)or GLAUCOMA. Untreate ...

mend wearing dark glasses in bright light to help protect the eye from light sensitivity. Swelling and irritation of the tissues ...

color deficiency A VISION IMPAIRMENT in which the ability to distinguish certain, and rarely all, colors is impaired. Color defi ...

ASTIGMATISM. Though the cornea has no BLOODves- sels it has numerous NERVEendings that make it highly sensitive. Because it is t ...

Corneal transplantation surgery takes place with a local anesthetic to numb the eye and an intravenous sedative medication for r ...