The disease causes damage to the retina at the young age of five to the age of thirty. It is more in males than in females, with a hereditary nature, and starts heading for the outskirts of the retina gradually toward the center and the first to complain about the patient is considered weak in the evening and in the dim light, and notes on the young parents with the disease of movement and difficulty in walking in dark places, and notice small objects.

In the growth of this disease, the patient begins to feel that consideration of the side being reduced to the extent that Itakbl like look at things through a tube or cylinder minutes. This situation continues to evolve to profoundly affect the intensity and strength of the consideration, but does not lead to blindness, and this disease is sometimes accompanied by white water in the lens, and the cause of this disease is not known exactly and move in heredity, there is no cure so far.

If one family member, it must be examined by others, to make sure they are free from