Q: I was watching the new Star Wars movie and shortly afterward I got some weird shimmering kaleidoscope-like images in my vision for half an hour. What’s up with that?

A: It sounds like you experienced an aura which are typical with a migraine. However, these auras are often painless events, perhaps for the majority of people who experience them. It’s not usually an eye problem. The effect occurs because of some subtle irritation in the visual part of the brain, which is actually near the back of the head. For instance, a sudden change in blood pressure or blood sugar may be enough to alter the circulation in that part of the brain. Other known causes would be food sensitivities or stress. Since these auras appear differently for everyone, it’s worth investigating with your eye doctor just to rule out the effect happening because of internal eye problems.

Dr. Alex Kennedy, www.mosaicvisioncare.com