CATERACT

What is it?

When a cataract develops it is a clouding or opacity of the lens which is inside the eye. People often describe cataract as 'looking through a chiffon scarf'. In order to understand what a cataract is, it is useful to learn a little about how the eye works.

Inside the eye, behind the coloured part of the eye (iris) with the black hole in the centre (pupil) is a lens. In the normal eye the lens is clear or transparent. It helps to focus light rays on to the tissue at the back of the eye (retina). When cataract develops the lens becomes cloudy and prevents the light rays passing into the retina. The picture that the retina receives becomes dull and fuzzy. Cataract usually forms slowly and people experience a gradual blurring of vision.

Who gets it?

Most forms of cataract develop in adult life. The normal process of ageing causes the lens to harden and become cloudy (opaque). This is called age-related cataract and it is the most common type. It can occur anytime after the age of 40.

Cataract is not caused by overuse of the eyes and using the eyes when cataract starts to develop will not make the cataract worse.

Babies can be born with this condition. This is called congenital cataract.

Cataract is more common in people who have certain diseases such as diabetes.

When should I go to the GP?

When cataract progresses to the point that it is interfering with daily activities and normal lifestyle, cataract surgery is usually indicated.

What tests will I need?

Before you come into hospital the outpatients department will carry out special tests to measure your eye. This helps decide the strength of intraocular lens you need.

You may also need tests for your general health, such as blood tests and electrocardiograph (ECG). This may involve a visit to the hospital about 2 weeks before the operation.

What is the traetment?

The treatment for cateracts is surgical removal. This is often done as a day-case.