A blackout before the eyes may be epilepsy, but it is not always epilepsy. It may also be caused by postural hypotension, hypoglycemia, and other reasons. 1. Epilepsy: If there is a history of epilepsy, and the seizure is caused by certain adverse factors, it may show a sudden blackness in front of the eyes, and may be accompanied by symptoms such as limb convulsions, foaming at the mouth, incontinence and so on. 2. Postural hypotension: Especially for those who are usually weak, if they suddenly get up quickly when they are in squatting, lying down or sitting position, they may induce postural hypotension, resulting in insufficient cerebral perfusion, which may lead to blackness in front of the eyes, and may be accompanied by dizziness, weakness and other manifestations. 3. Hypoglycemia: When hypoglycemia occurs, the tissues and organs of the whole body are not supplied with sufficient energy, which may cause ischemia and hypoxia of the brain tissue. When hypoglycemia is more serious, resulting in ischemia and hypoxia of the brain is more serious, it may show a black eye, may also be accompanied by panic, hand tremor and other symptoms. As you can see, the blackouts are not epilepsy, but may be caused by other reasons. If the symptoms of blackouts occur frequently or are accompanied by other discomforts, you should consult a doctor as soon as possible to clarify the cause of the disease and then give targeted treatment.