Cataracts

One in three people over the age of 65 has a cataract. Left untreated cataracts can significantly impair vision. However, a simple, routine operation that can be done as a day case will usually restore the sight.
What are cataracts?
Cataracts are cloudy or opaque areas that develop in the normally clear or transparent lens of the eye.
The lens sits inside the eye, behind the coloured iris. The job of the lens is to focus the light entering the eye. The lens must be transparent for us to see clearly and sharply.
What causes them?
Most forms of cataract develop in adult life. With normal ageing, the lens hardens and becomes cloudy.
Cataracts can also result from conditions such as diabetes, trauma to the eye and certain medications.
Some babies are born with cataracts, known as congenital cataracts.
Cataracts are not caused by overuse of the eyes. Also, using the eyes when cataracts start to develop will not worsen the condition.
What are the symptoms?
The sight becomes blurred or misty. Those who wear glasses may report that they seem dirty or scratched.
Bright sunshine and lights might dazzle - some see haloes around lights. This can be a particular problem when driving at night because of the glare from on-coming headlights.
In addition, colour vision may become faded or washed out.
How can it be treated?
The most effective treatment is to remove the damaged lens. The operation is usually done once the cataract has begun to interfere with the person's quality of life. For example, when the person finds it hard to read, get out and about and drive because of their deteriorating eyesight.
Typically, the surgery is carried out under local anaesthetic, meaning the patient will be awake during the operation but will feel no pain.
The eye is not taken out of the socket. The lens can be removed and replaced with a clear plastic lens by making a small cut in the eye that does not usually require stitching afterwards. This new lens will remain in the eye for good and should correct the eyesight.
The surgery generally takes about 20 minutes to complete and most patients can return home that same day.
After the surgery, the eye that has been operated on will be covered with a protective patch, which should generally be worn for the whole of the next day and then every night for the next month.
Eye drops should also be used for two months after the operation to protect against infection. Some people may also be sensitive to bright lights for a while and might find wearing a pair of dark glasses helpful.
Generally, normal activities, including going back to work, can be resumed a week after the surgery.
Some people notice an immediate improvement in their vision, but it will take the eye a few weeks to settle and for the vision to return to normal. Those who needed glasses before the operation may still need them afterwards because the surgery only corrects the cataract.
Are there any side effects?
Cataract surgery is extremely safe. Fewer than 2% of patients have serious complications.
There is a risk of infection. An accumulation of fluid in the back of the eye can also occur, causing blurring of the central vision.
One of the most common complications is thickening of the membrane behind the new lens in the months following the surgery, which is known as capsular opacity. This can be treated with lasers.