Cataracts
What is it?
A cataract is a loss of transparency in the normally clear lens of the eye. At first, a small, hazy spot may appear in the field of vision. Gradually (often over a period of years), as the lens grows more opaque, vision becomes more blurry, especially at night or in very bright light. About 75 percent of Americans over age 60 show some signs of cataracts. Advanced cases are easily treated with surgery (although most patients can postpone surgery for years).
What Causes It?
- Aging is the single greatest risk factor for cataracts, as cumulative exposure to the sun's ultraviolet rays over a lifetime appears to be a primary cause.
- Exposure to radiation, including x-rays and microwaves, may promote cataracts.
- Physical injury to or inflammation of the eye (for example, uveitis oriritis) may lead to cataracts.
- The long-term use of corticosteroid drugs, hereditary factors, and birth defects may be contributing factors.
- Cataracts may occur at a younger age in people with diabetes mellitus.
Prevention
- Wear sunglasses marked "general purpose" or "special purpose," or those that indicate they block at least 95 percent of ultraviolet-B (UVB) rays.
Diagnosis
- Eye examination by an ophthalmologist.
How to Treat It
- To minimize glare outdoors, wear a wide-brimmed hat and sunglasses.
- Indoors, use floor or desk lamps with incandescent bulbs instead of ceiling or fluorescent lights. Avoid pinpoint halogen lights, which cause the pupils to constrict. Installing dimmer controls is advised.
- When reading, try large-print books and newspapers.
- Surgery (successful in 95 percent of cases) is the only cure for cataracts. It can often be postponed indefinitely but is advised when cataracts interfere with normal activities. During the operation the lens is removed and replaced with a plastic intraocular lens implant. (Special contact lenses or eyeglasses may be used when an implant is ruled out.)
When to Call a Doctor
- See an ophthalmologist for any vision problems.
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Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.