More serious loss of sight can happen as the result of accidents, or from a variety of medical conditions. The most common conditions are:
Macular degeneration
Macular degeneration is an eye condition that can affect older adults and results in a loss of vision in the centre of the visual field. It can make it difficult, or sometimes impossible, to read or recognise faces, although enough peripheral vision remains to allow other activities of daily life. It affects people in different ways and at different rates.
For more information contact the Macular Society, or go to the NHS website or the RNIB website.
Glaucoma
Glaucoma affects about two out of every 100 people in the UK who are over 40. It's important to have your eyes tested regularly. If left untreated it can cause blindness. However if it's diagnosed and treated early enough, damage to your vision can be prevented.
For more information visit the glaucoma pages on the NHS website or go to the RNIB site
Cataracts
A cataract is a clouding of part of the eye - vision becomes blurred because the cataract is like a frosted glass. Many people over 60 have some cataract and the vast majority can be treated successfully.
There is more information about cataracts on the RNIB website and the NHS website.
Diabetic retinopathy
Diabetic retinopathy is a common complication of diabetes. It occurs when high blood sugar levels damage the cells at the back of the eye, known as the retina. If it is not treated it can lead to blindness.
There is more information about diabetic retinopathy on the RNIB website and the NHS website.
Retinitis pigmentosa (RP)
Retinitis pigmentosa (RP) is the name given to a diverse group of inherited eye disorders. These eye conditions affect a part of your eye called the retina. RP causes permanent changes to your vision but how quickly this happens and how it changes differs between people. These changes may include difficulty with vision in dim light or the dark, and the loss of your side or peripheral vision
For more information on RP go to the RNIB website