Cataracts

Cataracts are cloudy patches in the lens inside your eye. They can develop in one or both eyes. One eye can often be more affected than the other.

The lens is normally clear. It allows light to pass through to the back of your eye, helping you to see sharp images. If parts of the lens become cloudy (opaque), light cannot pass through the cloudy patches. Over time, these patches usually become bigger, and more of them develop. As less light is able to pass through the lens, your vision may become blurry or cloudy. The cloudier the lens becomes, the more your sight will be affected.

Cataracts are the main cause of impaired vision in the world, especially in developing countries. They affect men and women equally. In one UK research study, around 30% of people aged 65 and over had cataracts in one or both eyes that impaired their vision.

Cataracts are most commonly found in older people. These are called age-related cataracts. Rarely, babies can have cataracts when they are born (congenital cataracts).

Symptoms usually develop over many years, most commonly in older people. Gradually, more of the lens in your eye becomes cloudy. If your cataracts are mild, you may not notice any symptoms to start with. If you have cataracts in both eyes, one eye may be more affected than the other.

Blurred, cloudy or misty vision is the most common symptom of age-related cataracts. You may have small spots or dots in your vision - patches where your sight is not as clear. Your sight may be affected by the light. For example, you may find it more difficult to see If the light is dim, when the light is bright (such as on a very sunny day), or in bright artificial light.

Other ways that cataracts may affect your sight can include:

• The glare from bright lights may be dazzling or uncomfortable to look at
• Colours may look faded or less clear
• Reading, watching TV and other daily activities may be more difficult than they used to be.

If you wear glasses, you may find that they have become less effective. Less commonly, you may see a halo (a circle of light) around bright lights such as car headlights or streetlights. Another rare symptom of cataracts is double vision (seeing two images of an object instead of one). The symptoms of cataracts can be similar to the symptoms of other eye conditions. It is therefore important to see your Optometrist for a check-up.

Having a cataract removed is one of the most common operations in the UK, with between 250,000 and 300,000 performed each year. The treatment gives almost instant results and in most cases the surgeon will correct part of your prescription at the same time.

Normal Vision

The same scene viewed by a person with cataracts