Cataracts

WEB EXCLUSIVE / MARCH 2005
POSTGRADUATE MEDICINE
Update of a handout originally published in April 1996

Download this Patient Note in PDF format

By age 80, more than half of the people in the United States will notice that their eyesight is not as clear as it used to be--a change that is due to cataracts. A painless cloudiness that gradually covers or extends throughout the lens of the eye, a cataract blurs vision and gives images a brownish tint. The cloudiness is severe enough in some people that normal daily activities, such as driving and reading, become difficult or impossible.

What are cataracts?
Normally, the lens focuses light on the retina to produce clear vision. The cloudiness of a cataract keeps light rays from passing through to the retina and thus blurs vision. Cataracts can cause double vision and glare from lights and can decrease the ability to see colors and to drive at night. One or both eyes may have a cataract.

Cataracts often occur as a normal result of aging. They can also be caused by certain diseases (for example, diabetes), injury to the eye, overexposure to ultraviolet light from the sun, prolonged use of certain drugs (for example, steroids), smoking, or alcohol abuse. Cataracts seem to occur more frequently in some families.

How are cataracts diagnosed?
The diagnosis of cataracts is usually made by your primary care physician or after a complete eye examination by an eye specialist called an ophthalmologist.

How are cataracts treated?
If the cataracts aren't severe enough to interfere with daily activities, no treatment may be needed. But if the cloudiness becomes bothersome, a change in eyeglass prescription or the use of antiglare sunglasses, brighter lighting, or a magnifying lens may help. If cataracts are severe enough to interfere with day-to-day living or with eye examinations that are needed for another eye problem, surgery may be required.

This type of surgery, which is very common and safe, consists of removing the cloudy lens and, in most cases, replacing it with a plastic or silicone lens. Surgery usually lasts about an hour. Because only a local anesthetic (numbing eyedrops) and perhaps a mild sedative are used, most people are able to go home the day of surgery. However, they need to have someone drive them home from the hospital or surgical center. Eyedrops and an eye patch are usually needed for a couple of days, and strenuous activity must be avoided. If surgery is required in both eyes, it is usually performed on one eye at least a month before it is performed on the other.

Cataract surgery improves vision in about 90% of cases. However, people who have another eye disease, such as macular degeneration, glaucoma, or diabetic retinopathy, may still have some vision problems due to these conditions. In a small number of people, infection, bleeding, swelling, or detachment of the retina occurs after surgery and requires follow-up care. If any of the following problems occurs, the ophthalmologist should be contacted immediately:

• Pain that does not get better even with medication
• An unusual number of floaters or flashes of light
• Nausea
• Excessive coughing
• Loss of vision
• An injury to the eye

Because vision changes after cataract surgery, it is not uncommon that new glasses or contact lenses are needed. Sometimes, the lens that replaced the cloudy one also becomes cloudy months or years after surgery. In this case, a laser is used to clear the lens.

Is there any way to prevent cataracts?
Regularly wearing sunglasses, not smoking, and eating a healthy diet with plenty of green, leafy vegetables may delay the development of cataracts. Everyone over age 60 should have an eye examination at least once every 2 years.

For more information on cataracts National Eye Institute 31 Center Dr, MSC 2510 Bethesda, MD 20892 301-496-5248 http://www.nei.nih.gov American Academy of Ophthalmology PO Box 7424 San Francisco, CA 94120 415-561-8500 http://www.aao.org

This information is not a substitute for medical treatment.

Please send technical questions related to the Web site to Ann Harste