The lens inside your eye is normally clear and allows light to pass through to the back of the eye, however, if parts of the lens become cloudy (opaque), light is unable to pass through the cloudy patches, this is cataract. Over time, the cloudy patches usually become bigger, and more of them develop. As less light is able to pass through the lens, your vision is likely to become blurry or cloudy. The cloudier the lens becomes, the more your sight will be affected. Cataracts most commonly affect older people and are known as age-related cataracts. In the UK, it is estimated that more than half of people who are over 65 years of age have some cataract development in one or both eyes. If cataracts are mild, different powered glasses and brighter reading lights may enable you to function relatively normally. Once cataracts start interfering with daily activities such as cooking or getting dressed, surgery is usually recommended. Cataract operations are generally very successful with few complications.