What did you today? Oh, watched a light show in my mind.

I had my yearly migraine today. For the past 4 years, I've had an ocular migraine pretty much exactly once a year. Usually it's in late winter, around February or March, when spring is just hinting at appearing. It was late this year, but last year, I had two, so I think they're somehow averaging out.

If you've never had an ocular migraine before, here's about how it goes. First, I develop what I can only describe as a "hole" in my vision. It's always somewhere on the left side. I'll start to notice that I can't see things I should be seeing, and I have to do a lot of head cocking to get the entire picture. I don't see blackness; I just don't see what's there.  The best movie to describe this phase of the migraine is the Neverending Story, when the Rock Biter describes the Nothing.

Naturally, this is a terrifying experience. By now I recognize it as the first phase of a migraine, but part of me still wonders if this time it's something different, and I'm really going blind. Or having a stroke.

The second phase is the sparkly phase. The Nothing is replaced by a crack, running across the  left side of my field of vision, composed of sparkling lights. The crack transforms into a big sheet of dancing geometric shapes. The phenomenon moves around, usually working its way upward and leftward. It makes it hard to see, but the right side of my field of view is usually relatively clear.

As time passes, the sparkles gets less and less pronounced, until they are more like a grey shimmer that finally fades off to stage left, like some kind of theatrical transition. The entire weirdness usually runs its course in about a half an hour. Today mine started around 1:15 and was done by 1:46, with only a little weird feeling in my left eye and an annoying headache.

Unfortunately, the headache  stays long after the show is over. Some people's migraine headaches are crippling. Mine, fortunately, aren't that bad—or unfortunately, considering they're an extreme nuisance but not extreme enough for me to legitimately take a break from work for them. I usually just turn off the lights and wait for it to be over. The worst time I ever had a migraine was in the middle of a meeting, during which I had to pretend I was fine and that I really could see the people I was talking to.

I haven't figured out anything particular that causes these headaches, except that they usually crop up at the end of winter, and I haven't found anything to relieve them.  A friend told me caffeine is a good remedy for a migraine, so when this one started, I fixed myself a cup of iced tea. Maybe that wasn't enough caffeine, but it certainly didn't do anything to influence the intensity or duration of this particular migraine.

At least one thing is relatively certain. I've got a good few months before I have to go through this again.