A cataract is a cloudy area in the lens of the eye.
A normal lens is clear. It lets light pass to the back of the eye. A cataract blocks some of the light. As a cataract develops, it becomes harder for a person to see.
Cataract is a normal part of aging. About half of Americans ages 65 to 74 have cataract. About 70 percent of those age 75 and over have this condition.
Most people with cataract have a cataract in both eyes. However, one eye may be worse than the other because each cataract develops at a different rate.
Some people with cataract don’t even know it. Their cataract may be small, or the changes in their vision may not bother them very much. Other people who have cataract cannot see well enough to do the things they need or want to do.
What Are the Symptoms of Cataract?
Here are some signs of cataract:
- Cloudy, fuzzy, foggy, or filmy vision.
- Changes in the way you see colors.
- Problems driving at night because headlights seem too bright.
- Problems with glare from lamps or the sun.
- Frequent changes in your eyeglass prescription.
- Double vision.
- Better near vision for awhile only in farsighted people.
These symptoms also can be signs of other eye problems.
See your eye doctor to find out what you have and how it can be treated.
A regular eye exam is all that is needed to find a cataract. Your eye doctor will ask you to read a letter chart to see how sharp your sight is. You probably will get eye drops to enlarge your pupils (the round black centers of your eyes). This helps the doctor to see the inside of your eyes. The doctor will use a bright light to see whether your lenses are clear and to check for other problems in the back of your eyes.
Other eye tests may also be used occasionally to show how poorly you see with cataract or how well you might see after surgery:
- Glare test.
- Contrast sensitivity test.
- Potential vision test.
- Specular photographic microscopy.
Only a few people need these tests.
How is Cataract Treated?
A change in your glasses, stronger bifocals, or the use of magnifying lenses may help improve your vision and be treatment enough. The way to surgically treat a cataract is to remove all or part of the lens and replace it with an artificial lens.
Just because you have a cataract does not mean it must be removed immediately. Cataract surgery can almost always be put off until you are unhappy with the way you see.
Your eye doctor will tell you whether you are one of a small number of people who must have surgery. For example, your doctor may need to see or treat an eye problem that is behind the cataract. Or surgery may be required because a cataract is so large that it could cause blindness.