What are cataracts?

Cataracts are cloudy areas that form in the lens of the eye. The lens is normally clear. Poor vision results because the cloudiness interferes with light entering the eye. The opacities in the lens scatter the light, causing hazy vision, in the same way that a dirty window scatters light.

Are cataracts a kind of growth?

No. Cataracts are due to a change in the lens material. However, cataracts can become worse as more of the lens material changes.

What causes cataracts?

Most cataracts are a result of ageing and long-term exposure to ultraviolet light. Some are caused by injury and certain diseases and in rare cases by exposure to toxic materials and radiation. Occasionally cataracts are present at birth, due to the baby's mother having had rubella during the pregnancy, or due to genetic defects.

Do cataracts get worse?

Yes. The clouded areas become larger and denser and cause the patient's sight to become worse. The time taken for this to happen varies from a few months to many years.

Do cataracts affect both eyes?

Usually cataracts affect both eyes but often they develop at different rates in each eye.

How common are cataracts?

People older than 65 years often have signs of cataracts and should have their eyes examined regularly. However the extent of the cataract varies considerably between individuals of the same age.

Can cataracts cause blindness?

If untreated, cataracts can cause blindness. Blindness can be prevented by detecting the cataracts early and, if necessary, by having them removed surgically. Your optometrist will refer you to an eye specialist if they consider that you need medical treatment for your cataracts.

How well will I see if my lens is removed?

In most cases very well. Most patients have an intra-ocular lens (IOL) inserted at the time of surgery, with excellent results. This is a plastic lens which replaces your own cloudy lens. Patients may also need to wear spectacles or contact lenses.

What are the signs of cataracts?

Usually the development of cataracts is gradual with a painless worsening of sight. Other symptoms include blurred or hazy vision, spots before the eyes, double vision and a marked increase in sensitivity to glare.

How can I be sure I don't have cataracts?

An examination by your optometrist will reveal any changes that have occurred in the lens of the eye. Optometrists have special equipment which enables them to see changes in the lens which may lead to cataracts several years before any symptoms appear.

Can cataracts be prevented?

There is no proven method of preventing cataracts. Long-term exposure to ultraviolet light is thought to induce cataracts, so a brimmed hat and approved sunglasses should be worn in sunlight.

When should I have a cataract operation?

This varies with each patient. Usually cataract surgery is performed when the patient's vision interferes with daily life. Your optometrist will assist you in making this decision.

Is cataract removal a major operation?

Cataract surgery is now a relatively minor procedure. Often it is performed under a local anaesthetic. Depending on the patient, the surgery may be performed on an out-patient basis. This means that the patient attends a hospital or clinic for the surgery and is able to go home the same day. The surgery is performed by an ophthalmologist, a medical doctor who specialises in eye surgery. Your optometrist will refer you to an ophthalmologist if necessary.