Cataracts are cloudy patches in the lens of the eye that can make your vision blurry.

They may eventually lead to blindness if they are left untreated.

Cataracts can develop in one or both eyes, and over time the size of the cataract can get bigger until the whole lens is covered.

The lens of each eye should be clear in order for your eyes to work properly. The clear lens allows light to reach the retina at the back of the eye, which enables you to see things. With a cataract, less light can reach the retina, so your vision is affected.

A cataract can be present for a while before you notice you have one. However, having regular eye tests can spot cataracts in their early stages, so it's important to keep up to date with eye examinations. Ideally, you should have your sight checked by an optician every two years, although people over 60 years old may be required to have eye tests every year.

If you have a cataract, it will continue to develop. The only way to restore your vision is by having the cataract removed by surgery.

Cataract surgery is one of the most common and quickest surgeries performed, and many people are able to return to their usual daily routine after 24 hours.

When it should be done

If the cataract is getting in the way of your daily business and affects your ability to drive or read, you may need cataract surgery. Typical signs are blurred vision or dazzle from lights (such as oncoming car headlights).

Surgery to remove a cataract can now be done at any stage of development. In the past, people with cataracts were encouraged to wait until the condition was so bad that they could hardly see. Now, cataract surgery can be performed from an early stage to prevent further eye conditions developing, such as macular degeneration or diabetic retinopathy. If you are at risk of developing an eye condition caused by cataracts, your GP may recommend having cataract surgery.

Are there any alternatives to surgery?

New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help with the first signs of a cataract (slight blur at the edge of an image), but they won’t stop the cataract growing and blurring your vision. However, if your cataract isn’t interfering with your daily life you may decide not to have the operation straight away.

It’s safe to leave a cataract. It doesn’t become harder to remove if you decide to wait a while before having surgery.

What will happen if I don’t have the operation?

Without surgery your lens will gradually become so cloudy that you won’t be able to see any detail at all, although some light will always be distinguishable. There is no medication that can clear a cloudy lens.