Cataracts are a very common eye condition. The cataract causes a change in the lens of your eye which makes your sight cloudy reducing your ability to see. Cataracts get worse over time so your sight gets cloudier and your vision deteriorates, but the cataracts can usually be removed with surgery and replaced with an artificial lens to enable you to see more clearly again.
The information within these pages is in relation to cataracts in adults. Some children develop cataracts, called congenital cataracts, before or just after birth but these are usually dealt with in a different way to cataracts in adults.
How your eye works
Cataracts affect the lens of your eye. Your eye is shaped like a round ball, which has at the front of it a clear tissue called the cornea. Light enters your eye through your cornea and is focused by the lens on to the retina. The cornea does most of the focusing of the light that enters your eye with the lens fine-tuning the focusing.
Throughout your life, the shape of your lens changes to help you see things clearly in the distance and close up. This is called "accommodation of vision". As you get older, the lens’ ability to change shape as well as it used to is reduced. When this happens, most people can see clearly in the distance, but they aren't as good at seeing things close up.
The lens is normally clear so that light can pass directly through and focus on your retina. The lens is clear due to the way the cells in the lens are arranged. When someone develops a cataract, it changes the way the cells of the lens are arranged causing the lens to become cloudy instead of clear, resulting in a restriction of light passing through the lens and a reduction in the quality of your vision.
Symptoms
Cataracts usually develop slowly and although symptoms vary there are some common symptoms that many people experience. Most people will eventually develop a cataract in both eyes, though not necessarily at the same time. When a cataract starts to develop, you may feel your sight isn't quite right. If you wear glasses you may feel that your lenses appear dirty, even when they're clean. Gradually, you may find your sight becomes cloudier, making it harder to see.
You may also experience another common symptom associated with bright lights. Lights can seem to glare, or you may find for example that the headlights of a car are more dazzling than they used to be. There may also be a slight change in your colour vision with things appearing more yellow than before. Other colours may also seem to have changed and you may notice that colours look difference when you look at them with one eye as apposed to both eyes.
If you start noticing any of these changes you should have your eyes fully tested by an optometrist (optician) who will be able to tell whether you have a cataract or not.
If a cataract is ignored, your sight will become increasingly cloudy, resulting in a deterioration of your vision until it looks like you are viewing through a heavy net curtain or frosted glass. Even if your cataract is not dealt with until your vision is very poor, it can still be removed and your sight will be almost as it was before the cataract developed.
Most people choose to have their cataracts removed when the change in their vision starts to impact on everyday life. The timing of this varies from person to person, depending on their personal circumstances.
Whilst many people with cataracts are still legally able to drive your optometrist should be able to tell you if your sight is within the legal limits for driving or if you should be considering having your cataract removed.