Often the first sign of the disorder is an inability to see in low light and darkness (night blindness). Those affected usually develop a ring-shaped blind spot surrounding the center of their visual field. This blind spot then expands to affect both central and peripheral (side) vision. Eventually all vision is lost.
There is no effective treatment for retinitis pigmentosa. There is some evidence that taking vitamin A supplements may help delay the progress of the disease.
WebMD Medical Reference from Healthwise