A cataract is the name given to a loss of transparency of the clear lens within the eye. There can be many causes of cataract but they most commonly occur just as part of the normal ageing process. One of the functions of the lens within the eye is to protect the light sensitive film at the back of the eye (the retina) from harmful UV light. The lens within the eye absorbs the UV light and this sets off a photochemical reaction which causes the lens to lose transparency after 50 or 60 years.

As the lens becomes misty or cloudy, less light reaches the retina and this is one reason why we all need more light to see by, for example when reading, as we get older. In the early stages of cataract formation the problem can be managed with stronger glasses and greater illumination when reading, but there may come a time when the lens is so cloudy that the only way to restore clear vision is to remove the lens and replace it with a clear plastic lens in a cataract operation.

How many people have cataract ?

By the age of 60 it is inevitable that the lens within the eye will have lost some transparency – everybody gets cataract eventually but only some people are affected by it.


There are no eyedrops or eye supplements that have been proven to prevent the formation of cataract, although many have been tried and continue to be researched.

Once cataracts start interfering with daily activities such as cooking, getting dressed or driving, cataract surgery is recommended to remove the cloudy lens.

In a cataract operation, two small self sealing holes are made in the eye so that an ultrasonic probe can be positioned inside the lens with the cataract. This probe vibrates at high speed and dissolves the misty lens so that a clear plastic lens can be put in its place.

Cataract operations are one of the most common operations performed in the UK with 300,000 procedures performed each year.

A regular Eye Examination will help to ensure that cataract is diagnosed early so that the progress of the cataract can be monitored. Most cataracts slowly develop over many years but occasionally they can develop more rapidly