Cataract - A Cause of Poor Vision

This information was developed by the American Academy of Ophthalmology.

What is a Cataract?

A cataract (CAT-ah-rackt) is a clouding of the lens of the eye. The normal lens is clear and brings light into focus so we can see. A cataract can be compared to a window that is frosted or "fogged" with steam. It is a common cause of poor vision, especially for older people, but it can be treated.

• A cataract is not a film over the eye, or a cancer;
• it is not caused by using your eyes too much;
• it is not spread from one eye to the other.

If you have a cataract, you may have:

•     blurry vision with no pain;
•     glare or sensitivity to light;
•     many eyeglass prescription changes;
•     double vision in one eye;
•     a need to read with brighter light;
•     poor vision at night;
•     dull or yellowed colors.

How do I know if I have a cataract?

A complete exam by your ophthalmologist, a medical eye doctor, can find out if your eye has a cataract, and whether your eyes have any other problems.

What is the treatment for cataracts?

Surgery is the only way your eye doctor can remove a cataract.

However, if the cataract doesn't bother your vision much, a change of glasses may be all that you need to see better.

There are no medicines, foods, vitamins or exercises that have been shown to prevent or cure cataracts.

Sunglasses may slow down the growth of cataracts in people who are outdoors a lot.

When should surgery be done?

When your vision is so poor that it gets in the way of important daily activities (such as reading or driving), you should think about cataract surgery.

Cataracts do not need to be "ripe" before they can be taken out. How soon you have cataract surgery depends on how poor your vision is and how healthy your eyes are.

What is cataract surgery like?

Millions of people have cataract surgery each year, most without problems.

During cataract surgery, the cloudy lens is taken out of the eye. In most cases, the lens is replaced with a permanent lens because your eye needs a lens to see clearly. This is called an intraocular or in-the-eye lens.

As with any surgery a good result cannot be guaranteed, but vision usually improves.

If you have problems with your sight, see an ophthalmologist. He or she can tell you whether cataract or some other problem is causing your vision loss or discomfort, and help you decide if cataract surgery is the right choice.

The American Academy of Ophthalmology is an organization of 20,000 ophthalmologists (medical eye doctors) dedicated to preserving eye health and sight.