For me, ocular migraines precede the headache migraine. That is, I always have the ocular aura, then it’s followed by the migraine in an hour or so while I get to enjoy the pretty flashing lights and loss of other vision. However, if I take some Excedrin Migraine as soon as I notice the aura, it knocks it out and the headache never comes.
I asked my doctor, and this was her recommendation since I can’t identify any specific triggers - I get migraines only infrequently, so it’s really difficult to tell. I have started keeping the Excedrine Migraine in my desk at work though, just in case.
I kind of feel lucky - my migraines are a) infrequent and b) not so horrible. I mean, I hate them and they hurt like hell, but they don’t put me out of commission for all day (or worse, a day or two). They’re pretty much gone in 8ish hours or so - they’re always gone when I wake up the next day.