A cataract is a clouding of the lens in your eye. Your lens sits just behind your iris, the coloured part of your eye. Normally your lens is clear and helps to focus the light entering your eye. Developing cataracts will cause your sight to become cloudy and misty.
Cataracts can affect one or both eyes. Cataracts are treated by surgery, during which the cloudy lens is removed and replaced by an artificial lens.
Causes of cataracts
Developing cataracts is a normal part of growing older. Most people start to develop cataracts after the age of 65, but some people in their forties and fifties can also develop cataracts.
Certain things make it more likely that you will develop cataracts:
Diabetes – people who have diabetes often develop cataracts earlier.
Trauma – having an eye injury can cause the injured eye to develop a cataract.
Medications – some prescription drugs can cause cataracts, for example steroids.
Eye surgery – surgery for a retinal problem will likely lead to cataracts in the affected eye at some point in the future.
Cataracts normally develop very slowly. At first, the changes to your sight may be slight, but as your cataracts get worse you’ll start to notice symptoms such as:
You feel like your glasses are dirty and need cleaning, even when they don’t.
Your sight is misty and cloudy.
You’re more sensitive to light – bright sunlight or car headlamps may glare more.
Everything looks a little more washed out than it should be.
Eventually, almost all people with cataracts will find that their sight has turned misty or cloudy, and things have become difficult to see all of the time.
Cataracts can be removed by surgery. Cataract surgery removes your cloudy lens and replaces it with an artificial lens. This lens is known as an intra ocular lens – often shortened to IOL. The artificial lens is made of plastic or silicone, and will not need to be changed for the rest of your life.
There isn’t any medicine or drops that can remove cataracts – surgery is the only way to treat them.
Our Understanding Cataracts download guide (see the top of this page) goes into more detail on cataract surgery.