Example of Sight-
Retinitis Pigmentosa affects approximately 25,000 families in the UK and it is the largest untreatable cause of hereditary blindness in the young and those of working age. At present there is no treatment that can stop the progress of RP or cure it.
Retinitis Pigmentosa is the name given to a group of hereditary diseases of the retina, the light sensitive tissue in the back of the eye in which the first stages of seeing take place.
The word Retinitis implies a disease of the retina and Pigmentosa refers to the characteristic appearance of abnormal clumps of pigment, which occur in the retina during the advanced stages of the disease.
The retina slowly degenerates and loses its ability to transmit pictures to the brain. Often the first symptom is night blindness, followed by a narrowing of the field of vision. Sometimes the central vision is lost first, but in each case the loss is progressive often leading to complete loss of sight.
Some people with have other related problems, for example Ushers Syndrome, which is hearing loss as well as blindness and this obviously makes their situation even more difficult to live with.
Retinitis Pigmentosa is a genetic disease. There are three types: