Diagnosing Cataract - Cataract: The Aging Eye Preventing And Treating Eye Disease

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Diagnosing cataract

Cataract is painless and progresses slowly. Vision usually turns blurry or dim, and glare from lights and the sun becomes especially distressing. A person may experience double vision, as well as a distorted image; in the early stages, the eye may even become more nearsighted because the denser the lens, the greater its refracting power. Night vision worsens, and colors appear duller. Because most cataracts develop very slowly, people don't understand what is wrong until the decline in visual acuity forces them to seek frequent changes in their eyeglass or contact lens prescription. These efforts become fruitless, however, because corrective lenses cannot reverse the opacity of cataract.

Anyone who experiences blurring or eye discomfort should visit an ophthalmologist immediately for a full examination, because cataract is only one of several important diseases that affect vision (see "Symptoms requiring attention"). The doctor will test the sharpness of your vision with a Snellen chart (see "Testing your vision") and will probably dilate your pupils with drops. By examining the interior of the eye with a slit lamp, the doctor can see any cataract and assess just how extensive the cloudy patches are. Additional examinations and tests help rule out other eye disorders, such as glaucoma or retinal degeneration.

Last updated:	June 19, 2007