Anterior ischemic optic neuropathy (AION) is primarily a disease of middle and late life. When it affects the young patient, AION is often due to a specific underlying disease process predisposing to vasculopathy. Reported here are two patients with AION in whom no evidence of associated disease was found. The tendency for recurrent attacks of disc ischemia distinguishes this clinical entity from the more common idiopathic form of AION of older individuals. Hypotheses regarding possible etiology are discussed.