Q&A: To treat or not to treat visual migraines?

Every couple of months I get a visual migraine—flashing lights in my field of vision, but no headache. My ophthalmologist says not to worry and that I don't need any treatment. Is he right? —A.B.W., Jackson, Wyo 

Yes, as long as the episodes don't bother you much. Visual migraines, thought to stem from minor changes in blood flow in the brain,cause vision loss or disturbance characterized by flashing or shimmering lights, or black, gray, or white patches in the field of vision. They generally last anywhere from a few minutes to an hour, and can cause nausea. No treatment is necessary for occasional attacks, though you should make sure a doctor has ruled out other, more serious causes of sudden vision changes, such as a torn or detached retina. People whose attacks are very intense or occur more than once a week should talk to their doctor about taking a preventive drug, such as a beta-blocker or calcium channel blocker. Avoiding recognized triggers, such as stress, alcohol, oral contraceptives, and smoking, may also help.