Cataracts are a common feature of ageing, occurring in many people in their later years. They can cause visual problems and even complete loss of sight, but diagnosis and treatment are now routine in developed countries. Cataract surgery takes less than an hour and restores vision successfully in most people.

A cataract is a cloudy patch that develops in the normally transparent lens of the eye. As the lens clouds, vision becomes gradually mistier and more blurred, making it difficult to read, drive and carry out other everyday activities. As you get older, you may find you get cataracts in both eyes, but it is common for the cataract in one eye to be worse than the other.

Cataracts can develop in both men and women as they get older. In the UK, about one in 3 people over the age of 65 is believed to have some degree of cataract development in one or both of their eyes.

What symptoms do cataracts cause?

In the early stages, a cataract may not cause any noticeable problems; in fact, many people do not even realise they have one. Then as time goes on, the blurring will get worse and other symptoms of cataracts may develop. Poor night vision, seeing halos around lights and having trouble seeing in bright light can all become a problem.

Colours might also seem faded, or the world might look as if you are looking at it through a yellow filter. Some people experience double vision as the defects in the lens split the light, forming two separate images on the retina.

Most age-related cataracts get worse gradually over many years but the rate of loss of vision varies considerably from person to person. Eventually, in most cases, vision will noticeably deteriorate and, if left untreated, can lead to complete blindness in the affected eye.

Cataract diagnosis

An optician can usually spot a cataract during an eye examination, with early cataracts often detected during a routine eye check even before problems with vision have been noticed. This is usually followed by a referral to an ophthalmologist or an ophthalmic surgeon to plan your treatment.

Diagnosis of your cataract is confirmed by examining your eye with an ophthalmoscope. You may need to have eye drops first to make your pupil enlarge so that it is easier for the ophthalmologist to examine your eye’s lens.

Once an age-related cataract has been diagnosed, treatment may not be necessary if there are no symptoms or if sight is only mildly affected. If this is the case, stronger glasses or a brighter reading light are often recommended, both of which will help improve vision in the short-term.

In the longer term, as the impact of cataracts increases, surgery is the only way forward. The operation removes the clouded natural lens and replaces it with a clear artificial lens that gives good distance vision.