What is cataracts?


Cataracts: Overview

A cataract is a clouding of the lens of the eye. The lens focuses light on the retina at the back of the eye. Cataracts block some of the light and make it harder for you to see clearly. Cataracts often develop when you get older.

Most cataracts grow slowly. At first, you may just need stronger glasses to help you see better. Later, if the cataracts grow and begin to seriously impair your vision, you can have surgery to remove them.

What happens when you have cataracts?

As a cataract progresses, more of the lens becomes cloudy. When the entire lens is white, it causes severe vision problems. Delaying surgery until this point isn't recommended.

Cataracts may stay small and you may not notice them. They often don't seriously affect vision. Many cataracts don't need to be removed.

Some cataracts grow larger or denser over time, causing severe vision changes.

  • Decreased vision may affect driving, working, reading, or hobbies. This can cause a loss of independence.
  • A rare type of cataract can lead to glaucoma.

If treatment is available, it's rare for cataracts to cause blindness. Surgery is usually done before this happens.

Cataracts in children are rare but serious. If a cataract prevents light from entering a child's eye, the area of the brain used for sight does not develop the right way. Unless it's treated right away, the child won't see well with that eye.

What are the symptoms of cataracts?

Many times cataracts don't cause any vision problems. Symptoms can include cloudy, fuzzy, or foggy vision. You may have trouble driving at night because of glare from car headlights. The vision loss from a cataract often happens slowly. It may never become severe.

How are cataracts treated?

Surgery is the only way to remove a cataract. The surgery works well and helps people see better. But surgery may not be needed or can be delayed for months or years. Many people with cataracts get along very well with the help of eyeglasses, contact lenses, and other vision aids.

How can you prevent cataracts?

There is no proven way to prevent cataracts. But you may be able to slow cataract growth. For example, don't smoke. Wear a hat or sunglasses when you're in the sun, and avoid sun lamps and tanning booths. Eat healthy foods. If you have diabetes, manage your blood sugar levels.

How are cataracts diagnosed?

Your doctor can find out if you have cataracts by checking your eyes and by asking questions about your symptoms and past health. You may need tests to make sure you have a cataract or to rule out other conditions that may be causing vision problems.

Who can diagnose and treat cataracts?

The following health professionals can evaluate vision problems that may be caused by a cataract:

  • Ophthalmologist
  • Optometrist
  • Nurse practitioner
  • Physician assistant
  • Family medicine physician
  • Internist
  • Pediatrician

While other doctors may be able to detect problems that may be caused by cataracts, only an ophthalmologist can treat cataracts.

How can you care for yourself when you have cataracts?

Try these tips to manage your vision problems at home. Use soft background light and task lighting. Avoid glare from screens by moving lights or using shades. Keep your glasses or contact lens prescription up to date. Wear sunglassses that screen out UVA and UVB rays. Try magnifying glasses to help with reading.

How is surgery used to treat cataracts?

In surgery for cataracts, the cataract is removed and replaced with an artificial lens. For most adults, surgery is needed only when vision loss caused by a cataract affects their quality of life. Chances of seeing better after surgery are very good. But you may still need glasses to read or for night driving.

What increases your risk of cataracts?

Things that increase your risk for cataracts include:

  • Older age.
  • A family history of cataracts or certain genetic conditions.
  • Diabetes. Persistent high blood sugar (glucose) levels can damage the lens of the eye.
  • Surgery to treat glaucoma.
  • Smoking. This can make chemicals called free radicals form. High levels of free radicals can damage cells, including those in the lens of the eye.
  • Infection during pregnancy, such as rubella or chickenpox. These may cause the baby to develop a cataract before birth.
  • Exposure to ultraviolet light.
  • Long-term use of high doses of steroid medicines. These may be used for conditions such as asthma or emphysema.


Lens of the eye clouded by a cataract

A cataract is a partial or complete cloudiness in the lens in the eye. The lens is enclosed by the lens capsule. The cornea is the clear outer layer at the front of the eye.

What causes cataracts?

Aging and exposure to sunlight can cause cataracts. But eye changes caused by aging don't always lead to cataracts. Cataracts can also happen after an eye injury, as a result of eye disease, after you use certain medicines, or as a result of health problems such as diabetes.

Cataracts: When to call

Watch closely for changes in your health, and be sure to contact your doctor if:

  • Your vision is getting worse.
  • You have increasing trouble doing everyday tasks, like driving or reading the newspaper, because of your eyesight.

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The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.