A visual migraine is a common cause of temporary sight problems that may or may not be accompanied by headaches. An episode occurs when the tiny blood vessels that feed the retina become constricted, reducing blood flow to the eye. In most cases, a visual migraine affects only one eye and lasts for less than 30 minutes. Visual migraines are usually harmless to a person's overall health, though an individual who experiences frequent or severe episodes should meet with a doctor to rule out more serious underlying problems and discuss ways to manage the condition.
Blood vessel constriction can be caused by a number of different factors. Most episodes are related to seemingly innocuous causes, such as standing up too quickly or engaging in moderate exercise. Hormonal imbalances, viral infections, and blood disorders such as sickle cell anemia can also cause visual migraines. Some people also experience symptoms that are triggered by adverse reactions to prescription or over-the-counter drugs.
The first sign of a visual migraine is a gradually widening blind spot in the center of vision. Many people see shimmering dots or flashes of light in their peripheral vision. Distorted images can cause a person to become dizzy, nauseous, or lightheaded. A visual migraine typically lasts for less than five minutes, and problems rarely persist for more than a half hour. Sight returns quickly, though symptoms of nausea or a mild headache may persist.
It is important for a person who experiences a visual migraine to visit an emergency room or schedule an appointment with an ophthalmologist for a thorough evaluation. A doctor can check for signs of eye disease, vascular disease, or a detached retina by taking diagnostic imaging scans and carefully examining the eye. He or she may perform blood tests to look for drug toxins or signs of anemia.
Treatment for a visual migraine depends on the underlying cause. Patients who do not appear to have medical problems do not normally require medical care. They are simply sent home and instructed to return if problems recur for further analysis. If a drug reaction is responsible, a patient may need to switch medications.
A visual migraine that affects both eyes simultaneously is likely a symptom of the more conventional definition of a migraine. The phenomenon is called an aura, and typically precedes the onset of a severe headache. A person who experiences migraines with auras should seek immediate medical care to receive a thorough neurological screening and learn about different medicines to reduce pain and the frequency of episodes.