Cataracts affect the lens of the eye, causing vision to become cloudier. It's estimated that around 2.5 million people aged 65 or over have a visual impairment caused by cataracts.

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What are cataracts?

Cataracts affects the lens of the eye making it more difficult for light to pass through and focus on the retina, causing ‘cloudy’ central vision. This can make it difficult to see details, colours, recognise people, read and undertake detailed tasks.

Cataracts most commonly occur in people aged over 40, when the cells in the lens begin to degrade and create clusters of protein. Cataracts can also be caused by injury, and as a secondary condition for people with other eye or health conditions, such as retinitis pigmentosa or diabetes. More rarely, cataracts can be congenital, appearing from birth or soon after (even if cataracts are removed at an early age visual  development can be affected), or as a side effect of long-term use of certain drugs.


Different types of cataract cloud the lens in different ways but parts of your visual field are likely to be affected.


Across the world, cataracts are a common cause of sight loss but they are less common in developed countries where treatment by surgery is more accessible. Left without treatment, it’s possible for cataracts to affect your entire visual field, completely ‘clouding’ your vision.

Practical implications

 Your day to day life is likely to be affected if you have cataracts but the impact will vary, depending on which area of your visual field is affected and on the type and severity of the cataract. If you have clouded central vision, you’ll find it more difficult to see details, colours, recognise people, read and undertake fine detailed tasks.   

Cataracts can cause sensitivity to light and glare, which can be both uncomfortable and affect your vision. If you experience glare from lightbulbs in the home, for example, you might want to choose covered lightshades that disperse light evenly in the room.

A picture of a man using a magnifying glass to read a bottle

Find strategies that work for you 

Our series of helpful hints and tips will help you maintain your independence while learning new skills and strategies.

Find out more about symptoms, diagnosis and treatment on the NHS website.