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The term visual impairment refers to someone who is blind or partially sighted. It does not refer to someone who is short-sighted (myopia) or long-sighted (hyperopia).


Worldwide, about 314 million people are visually impaired. Of these, approximately 14% (45 million) are blind.

Most people (87%) who are visually impaired live in developing countries. In developing countries, cataracts (a cloudy area that forms in the lens of the eye) are responsible for most cases of blindness (48%).

With the right treatment, about 85% of visual impairment cases are avoidable, and approximately 75% of all blindness can be treated or prevented.

Due to improved public health, the number of people who become blind after having an infectious disease has fallen over recent years. However, age-related visual impairment is increasing.

Visual impairment usually affects older people. Globally, women are more at risk than men.

Partial sightedness and blindness

If you are visually impaired, you will have some loss of vision or some distortion to your vision. Depending on the severity of your sight loss or the degree of distortion, the conditions are usually referred to as partial sightedness or blindness.

Partial sightedness

Someone who is partially sighted has a serious loss of sight but they are not blind.

The World Health Organization (WHO) defines partial sightedness as where a person cannot clearly see how many fingers are being held up at a distance of 6m (19 feet) or less, even when they are wearing glasses or contact lenses.


WHO defines blindness as severe sight loss, where a person is unable to see clearly how many fingers are being held up at a distance of 3m (9.8 feet) or less, even when they are wearing glasses or contact lenses. However, someone who is blind may still have some degree of vision.


Visual impairment can have serious implications for driving. If you have a medical condition or disability, such as partial sightedness or blindness, you must inform the Driver and Vehicle Licensing Agency (DVLA). Failure to do so is a criminal offence and is punishable by a fine of up to £1,000.

Last reviewed: 31/08/2009
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Last modified: Oct 2016