Cataracts

Statistics

Global [1]

Global causes of blindness as a proportion of total blindness in 2002: Cataracts 47.8%

Background
The lens is a clear tissue found behind the iris, the coloured part of the eye. The lens helps to focus light on the back of the eye - the retina - forming an image.

What is a cataract?
A cataract is a clouding of the lens. Your vision becomes blurred because the cataract is like frosted glass, interfering with your sight.

Causes
Cataracts can form at any age. Most develop as people get older but we don't yet know why, although research is being done into a number of possible causes. In younger people we know that they can result from conditions such as diabetes, certain medications and alongside other longstanding eye problems.

Effects
Blurry sight - This is very common. You may notice that your sight has become blurred or misty, or that your glasses seem dirty or appear scratched.

Dazzled by light - You may be dazzled by lights, such as car headlamps, and sunlight.

Change of colour vision - Your colour vision may become washed out or faded.

Further information

Acknowledgements

The information contained in this section was collected from the following source:

Royal National Institute of the Blind (RNIB)

[1] World Health Organisation (2004) Magnitude and causes of visual impairment. [accessed 29/01/08].