Cataracts are cloudy patches in the lens (the transparent structure at the front of the eye) that can make vision blurred or misty. They can develop in one or both eyes, and one eye can often be more affected than the other.

The lens

The lens is normally clear and allows light to pass through to the back of the eye.

However, if parts of the lens become cloudy (opaque), light is unable to pass through the cloudy patches.

Over time, the cloudy patches usually become bigger, and more of them develop. As less light is able to pass through the lens, the person’s vision is likely to become blurry or cloudy. The cloudier the lens becomes, the more the person’s sight will be affected.

How common are age-related cataracts?

Cataracts are the main cause of impaired vision in the world, particularly in developing countries. They affect men and women equally.

Cataracts most commonly affect older people. Cataracts that affect older people are known as age-related cataracts. In the UK, it is estimated that more than half of people who are over 65 years of age have some cataract development in one or both eyes.

Childhood cataracts

In rare cases, babies have cataracts when they are born, or children develop them at a young age. See the Health A-Z topic about Childhood cataracts for more information.

Outlook

If cataracts are mild, stronger glasses and brighter reading lights may enable people to live with the condition. However, if left untreated, cataracts can cause blindness.

Once cataracts start interfering with daily activities such as cooking or getting dressed, surgery is usually recommended. It is estimated that around 10 million cataract operations are performed around the world each year. Cataract operations are generally very successful with few complications.

If you have cataracts, it could affect your ability to drive. It is important that you inform your doctor and the Road Safety Authority (RSA) about a medical condition that could have an impact on your driving ability.

Glossary

Lens

The transparent structure at the front of your eye, just behind your pupil (the black circle in the centre of your eye).