Facts on File Encyclopedia of Health and Medicine

added to the corrective prescription, that accom- modates the limited ability of the lens to focus on near objects (such as when ...

cause corneal ABRASIONS, particularly in dusty, windy, or dry environmental conditions. Contact lenses tend to accumulate protei ...

D dacryocystitis INFLAMMATION of the lacrimal (tear) ducts, typically the nasolacrimal ducts in the corners of the EYEnear the N ...

See also AGING, VISION AND EYE CHANGES THAT OCCUR WITH; ELECTRORETINOGRAPHY; NIGHT BLINDNESS; RETINITIS PIGMENTOSA; RETINOPATHY. ...

E ectropion Loss of elasticity or control of the eye- lid, usually the lower eyelid, that causes it to sag away from the EYE. Ec ...

enucleation Surgical removal of a cancerous EYE or a severely diseased or damaged eye. The OPERA- TION, performed under general ...

eye The organ of vision. The paired eyes work in coordination to present NERVEimpulses the BRAIN interprets as dimensional (ster ...

from scratchy irritation to intense and debilitating pain. Much eye pain in the form of burning and itching arises from minor an ...

F farsightedness See HYPEROPIA. flashes Visual phantoms that appear as spots of light. An ophthalmologist should evaluate occur- ...

G glaucoma A serious and progressive EYEcondi- tion in which the cells at the front of the OPTIC NERVEwhere it intersects with t ...

pattern of progression begins with loss of periph- eral (outside) vision. Over time the field of vision becomes increasingly nar ...

medication therapy. Surgical treatments for glau- coma include the following: For iridotomy, the ophthalmologist uses an ophtha ...

CONJUNCTIVITIS(inflammation of the inner eye- lids) diminished visual acuity (blurry or distorted vision) PHOTOPHOBIA(sensitivi ...

H hordeolum A bacterial INFECTIONof a gland or an eyelash follicle along the edge of the eyelid, com- monly known as a stye. A h ...

I intraocular pressure The pressure within the EYE that maintains the eye’s form and structure. Nor- mal intraocular pressure in ...

complete VISION IMPAIRMENT. There are two forms: arteritic, associated with giant-cell arteritis (an inflammatory disorder of th ...

K keratitis INFLAMMATIONof the CORNEA, usually the result of anINFECTION. The cause of the infection is more commonly viral, suc ...

L–M lens The primary focusing structure of the EYE, located in the center at the front of the eye. The lens is transparent, conv ...

difficulty seeing the ball when playing baseball, tennis, and similar sports frequent headaches at the end of the day CORRECTI ...

N nearsightedness See MYOPIA. night blindness Impaired dark adaptation result- ing from slowed photochemical reactions in the ro ...