Retinitis pigmentosa (RP) is a herditary disease of the retina which results in blindness. The outer segments of retina and sperm rich in docosahexaenoic acid (C22:6). Previous studies in animals have shown that deprivation of C22:6 or its precursors may cause visual defects. The hypothesis in the proposed research is that abnormalities in the metabolism of docosahexaenoic acid may well be a problem in the RP syndrome.