An attack of abrupt loss of vision in one eye that recovers completely after a short period is called "transient monocular blindness" (TMB) or amaurosis fugax. The most common cause of TMB is atherothromboembolism from the origin of the internal carotid artery (ICA), whereas atrial fibrillation is quite uncommon. TMB also can be caused by anterior optic nerve ischemia, that is usually caused by thrombosis in the posterior ciliary artery. Thrombosis in the central retinal vein may be another cause. Dissection of the ICA, vascular malformations, or fibromuscular dysplasia are other potential etiologies. Blurring of vision as compared with blackened vision or positive phenomena such as flashing is probably associated with a higher risk of future cardiovascular events, whereas involvement of the partial monocular field is associated with a relative benign prognosis. In patients with atherosclerosis, antiplatelet therapy is indicated and treatment of vascular risk factors should have high priority. Carotid endarterectomy should be performed only in case of an ICA stenosis of more than 70% in the presence of at least one other risk factor for stroke.