A few years ago, I was working in the lab when I noticed that my vision was going wacky. I wrote all about it on my blog which you can read here. Well, today I was reading In the Pipeline and one commenter mentioned fortifications hallucination. So I looked that up and found the wikipedia article, scintillating scotoma, which pretty exactly describes what I was seeing. The Wiki article even has some pretty good graphics.
Now I have a little better idea of what was going on. I never did get a migraine and this never happened again.