Astigmatism is a condition in which the cornea (the clear covering of the front of the eye) has an abnormal curve, causing out-of-focus vision.
Causes, incidence, and risk factors:
The cause of astigmatism is unknown. It is usually present from birth, and often occurs together with nearsightedness or farsightedness. A minor degree of astigmatism is considered normal and does not require correction. Astigmatism is very common.
Symptoms:
Difficulty in seeing fine detail, either close-up or from a distance.
Signs and tests:
Astigmatism is easily diagnosed by a standard ophthalmic exam with refraction test. Special tests are not usually required. Children or others who cannot respond to questions can have the degree of their vision problem measured by a test that uses reflected light (retinoscopy).
Review Date: 8/8/2006
Reviewed By: Paul B. Griggs, MD, Department of Ophthalmology, Virginia Mason Medical Center, Seattle, WA. Review provided by VeriMed Healthcare Network.
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General Eye Care
