The authors analyzed the racial distribution of optic nerve head drusen and nonar-teritic ischemic optic neuropathy in a clinical setting. Blacks had a significantly much lower incidence of these two disorders than whites. Knowing previously that both disc drusen and nonarteritic ischemic optic neuropathy are associated with small discs, and that blacks have a larger disc area than whites, the authors conclude that blacks have a lower incidence of optic nerve head drusen and nonarteritic ischemic optic neuropathy than whites, partly because of racial variation of the optic disc size.