Cataract occurs when the lens inside the eye becomes cloudy (see ‘How the human eye works’) causing vision to become misty or blurred. It is not a skin growing over your eye, despite what you may have heard.
Most cataract is ‘age related cataract’. As we go through life our lenses naturally lose some clarity and so cataract is very common in people over the age of 60. Early cataracts do not affect your vision and do not require treatment.
Sometimes babies are born with (‘congenital’) cataract in one or both eyes. This is due to factors affecting the baby during its development. The information in this article relates to age related cataract. To find out more about congenital cataract you can visit the RNIB website at the end of this article.
How would I know if I had a cataract?
Cataracts are not painful but can affect your vision in several ways.
People with cataract often notice that their vision seems misty or blurred and perhaps get the feeling that they need to clean their glasses. Although cataracts tend to affect both eyes, one eye is usually more affected than the other, so you may only notice these symptoms in one eye. People often notice that it is hard to recognise people’s faces when you see them down the road or that the golf ball disappears against the sky.
Drivers with cataract are usually more troubled by the glare of oncoming headlights or the sun when it is low in the sky.
What causes cataract?
The transparency of the lens in the eye is due to the very regular arrangement of the cells that make up the lens. As we go through life this arrangement is gradually disturbed causing the lens to become cloudy. In this sense, everyone will eventually develop cataract to some degree and so age is the biggest risk factor in cataract. However, some people develop cataract at an earlier age than others. This may be partly hereditary but other factors such as exposure to ultraviolet light, smoking, eye injuries and other diseases or medication are important.
Can cataracts be prevented?
We can’t help getting older but we can reduce the risk of cataract by:
Not smoking! Oxidising agents in cigarettes are known to accelerate the process of cataract.
Protect your eyes from the sun. This is particularly important for children as their eyes are more susceptible to the effects of sunlight. It has been estimated that by the age of twenty an individual will have received 80% of their lifetime exposure to ultraviolet light. So wear good UV absorbing sunglasses to protect your eyes.
Can cataracts be treated?
Treatment of cataract requires surgery to remove the cloudy lens from the eye. Cataract cannot be treated by ‘laser.’ In recent years the techniques for cataract surgery have improved dramatically. The surgery is usually performed under local anaesthesia to help the patient recover more quickly and avoid the need to stay overnight in hospital. Using a special instrument the surgeon breaks up the cataract into tiny pieces which can then be easily removed from the eye before a new plastic lens is inserted into the eye to replace the old lens and help the eye to focus.
More useful information about cataract can be found at the following websites: