It is a genetic disorder in the eye, which affects the retina, and this disorder is a result of a defect in the light receptors of the retina.
· Decreased or loss of night vision
· Loss of peripheral vision gradually (tunnel vision).
· Difficulty with color vision.
· Vision decreases but not rapidly, it may last for years.
There is no cure now for the disease but the doctors follow ways to delay progression of the disease.
· Use sunglasses to protect the eyes from ultraviolet rays.
· Eyeglasses and magnifiers, especially for early treatment.
· Intensity of external light helps to improve vision.
· Treatment with Vitamin (A) is beneficial for cases where this vitamin is lacking, but not for other types, and should only use as directed under medical supervision.