Transient blackout in one eye is a type of ischemic retinopathy. The blood supply to the retina comes mainly from the central retinal artery. The latter is the major artery supplying blood to the brain. Since the central retinal artery is the terminal artery, when vasospasm occurs under certain triggers, or when a thrombus embolus blocks it, acute ischemia occurs in the retina, and the patient develops the manifestation of transient blackout described above. If the vasospasm continues unrelieved or the embolus cannot be removed and retinal blood perfusion cannot be restored in time, serious consequences such as eye blindness may result. Inexplicable sudden blindness in one eye, after a minute or a few minutes and then well again, and some of them recur several times, and some of them will also have hemianesthesia, sudden inactivity of limbs, etc., or even hemiplegia, a few days or a few months after the occurrence of the above situation.