Don’t lose sight of cataract

Information for people at risk

1. What is a cataract?

A cataract is a clouding of the eye’s lens that

causes loss of vision. This brochure is about 

age-related cataract, the most common type.

2. What causes it?

The lens lies behind the iris and the pupil. It

works much like a camera lens. It focuses light

onto the retina at the back of the eye, where an

image is recorded. The lens also adjusts the

eye’s focus, letting us see things clearly both up

close and far away.

The lens is made of mostly water and protein.

The protein is arranged in a precise way that

keeps the lens clear and lets light pass through it.

But as we age, some of the protein may clump

together and start to cloud a small area of the

lens. This is a cataract. Over time, the cataract

may grow larger and cloud more of the lens,

making it harder to see.

Researchers suspect that there are several causes

of cataract, such as smoking and diabetes. Or, it

may be that the protein in the lens just changes

from the wear and tear it takes over the years.

3. When are you most likely to

have a cataract?

The term “age-related” is a little misleading.

You don’t have to be a senior citizen to get this

type of cataract. People can have an age-related

cataract in their 40s and 50s. But during middle

age, most cataracts are small and don’t affect

vision. It is after age 60 that most cataracts steal

vision.

4. What are its symptoms?

A cataract starts out small. It has little effect on

vision at first. You may notice that your vision is

blurred a little, like looking through a cloudy

piece of glass.

A cataract may make light from the sun or a

lamp seem too bright, causing a glare. Or you

may notice when you drive at night that the

oncoming headlights cause more glare than

before. Also, colors may not appear as bright to

you as they once did.

As the cataract gets bigger and clouds more of

the lens (doctors use the term, “ripens”), you

will find it harder to read and do other normal

tasks. The word “cataract” means waterfall. For

people with a ripe cataract, it is like trying to see

through a waterfall.

5. How is a cataract detected?

Although you might think you have a cataract,

the only way to know for sure is by having an

eye examination. Should your eye care professional find one, he or she can monitor it and

advise you about any future treatment.
6. How is a cataract treated?

It is treated with surgery. Your eye care professional will remove your clouded lens and, in

most cases, replace it with a clear, plastic lens.

Cataract surgery is very successful in restoring

vision. It is one of the most common surgeries

performed in the United States, with over 1.5

million cataract surgeries done each year.

7. When should a cataract be

treated?

If your eye care professional finds a cataract,

you may not need cataract surgery for several

years. In fact, you might never need cataract

surgery. By having your vision tested regularly,

you and your eye care professional can discuss if

and when you might need treatment.

8. What research is being

done?

The National Eye Institute (NEI), one of the

Federal government’s National Institutes of

Health, supports research on the lens and agerelated cataract. Most of these studies focus on

controlling cataract with drugs so that surgery

will not be needed. Although these drugs are

not yet available to patients, research is moving

forward in this area. The NEI is also evaluating

whether certain vitamins and minerals might

prevent or slow the progress of cataract. We

should know more about whether this treatment

works in the coming years.

9. What can you do to protect

your vision?

If you are over age 60, you should have an eye

examination at least once every two years. This

exam should include dilating your pupils. This

means drops are put into your eyes to enlarge

your pupils. Although a cataract can be detected

without dilated pupils, your eye care professional

can see the back of your eye better using this

exam. Getting a good view of the retina and optic

nerve is important in detecting eye diseases such

as glaucoma and macular degeneration.

To learn more about cataract, write: 

National Eye Health Education Program

2020 Vision Place

Bethesda, MD 

20892–3655

PDF Version—March 2000