I get auras with migraines too. And have had the lightning bolt type of thing MANY times.
The best thing to do, if it is a migraine, is to take something (I used to take Excederin migraine which is a combo of acetaminophen, aspirin, and caffeine), and then lay down.

If you are having migraines frequently, your doctor might prescribe something to try to prevent migraines.

If an over the counter medication doesn't help, there's a lot of migraine specific medications available by prescription that you take at the first symptom of a migraine (flashes, blurred vision are my typical signs).