Health Topics for Eyes and Vision

Department of Ophthalmology and Visual Sciences

Ophthalmology and Visual Sciences

Refractive Surgery

Cataracts

Cataracts are a clouding of the lens of the eye. The lens of the eye is a clear oval structure with three layers. The lens works like a camera lens. It focuses light onto the retina in the back of the eye where the image is recorded. The retina is the light sensitive tissue that takes these images and sends signals to the brain. The lens also adjusts the eyes focus, so we can see things clearly both up close and far away.

The lens is made of mostly protein and water. This protein is arranged in a special way to keep the lens clear and let light pass through it. Cataracts are produced when this protein starts to clump together. Clumping does cause the lens to become cloudy.

Although most commonly associated with older age, cataracts can also occur in children. Adults who get cataracts in their 40s and 50s, have few problems because the cataracts are usually small and do not interfere with vision.

It still is not certain what causes these changes in the eye. Research suggests that aging, lifelong exposure to ultraviolet light (usually sunlight), smoking, heredity, eye injuries, high cholesterol and triglycerides, taking cortisone medications for a long time, and diabetes are factors that may increase the risk.

Symptoms of cataracts may include:

• cloudy, foggy, or filmy vision not corrected with eyeglasses or contact lenses
• glare from lamps, sunlight, or snow
• blurred or double vision
• decreased night vision
• light sensitivity
• dulling of colors
• frequent eyeglass prescription changes and
• stronger glasses failing to improve sight

Small cataracts require periodic monitoring only. Larger ones may require glasses or other treatment. Surgery is needed to replace a lens when normal vision is blocked. It is done under local anesthesia and takes about an hour.

Good health habits may postpone or prevent cataracts. Eat a diet high in vitamins C and E and beta-carotene. Doing so may help prevent cataracts. Wear hats and sunglasses that protect against ultraviolet light. Stop smoking, since smokers are twice as likely to develop cataracts as nonsmokers.

Last Reviewed: 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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