Ocular changes due to chronic ischaemia are described in 45 patients with hemodynamically significant carotid occlusive disease. Regarding the ophthalmic artery flow before and after vasodilatory stimulus, the patients were divided into four different groups. Eyes with permanent anterograde ophthalmic artery flow had evidence of embolic features, but no signs of chronic hypoperfusion. In the group where anterograde ophthalmic artery flow changed to retrograde after 1 g intravenous acetazolamide, the patients had symptoms of critical ocular perfusion, but only subtle structural changes could be demonstrated. Chronic ocular ischaemic syndromes were found in the cases with retrograde ophthalmic artery flow, especially where bilateral severe carotid obstruction was present.