A:
An aura is the visual change that comes before a migraine headache. While 80 percent of migraine sufferers never experience an aura, there are a few people who have the visual symptoms of a migraine but don't experience a headache. This is sometimes called a visual or ocular migraine, an acephalgic migraine, or a migraine equivalent (the current technical term is "migraine aura without headache").
The visual changes that occur during a migraine aura can take many forms. They are usually described as flashing or scintillating lights. They may have a zigzag or "fortress-like" appearance, or look like poor reception on a television. Migraine auras typically start small, march across the field of vision, and then fade away. An attack will last for at least several minutes but usually no longer than an hour. If a headache follows the aura, it usually does so within an hour. Most people who have migraine auras will have the same type of symptoms with each attack.
However, not all episodes of flashing lights or visual changes are caused by migraines. Other important causes include:
Migraines are the likely diagnosis if you have been experiencing the same symptoms over many years. However, you should see your doctor if your visual changes are new or don't follow the typical pattern of migraines.
