Exactly the same trigger here. I had one just the other day at the pub. Sitting outside, under shade, but to my left was a bright spot. It’s weird how I can sense it arriving ... something about the quality of my vision subtly changes, and there it is.
Fortunately for me it isn’t accompanied by a headache. It’s just really unsettling. At least now I’ve learned to recognise them and I just try to chill out while it does its thing.
(FWIW, also a tremendous consumer of caffeine here. But this was at 17:00, a good 5 hours after my last cup.)
For whatever it’s worth, too much caffeine and dehydration does this to me. Chugging about 48 oz of water and throwing on a face mask for 30-60 minutes usually clears it up. If I do “nothing” it takes significantly longer to clear up.
In my case it's the combination of too much caffeine, dehydration, and intense exercise where my HR maxes out. 2/3 risk factors will typically not be enough to trigger one for me. HIIT workouts and soccer have done it in the past.
The aura (with scintillating scotoma) starts coming on usually an hour or so after the exercise is done, and I know I've got about 15-20 minutes before the actual migraine hits. Got prescribed Sumatriptan and it maybe reduced the intensity by about 25%. I'll have to try the water chugging, maybe with rehydration salts to speed up absorption.
I get the same, and all of these tend to be a trigger for me too -- too much caffeine, dehydration, and rapid light intensity change (like looking outside and then back to my computer screen).
In addition to chugging water and staying in the dark with a face mask, I've found that taking raw honey right as it's coming on makes it go away rapidly.
My long term prevention is taking magnesium daily and LSD once or so a year. Once I started doing that the frequency went to almost zero, and whenever I don't do that they start up again.
Fortunately for me it isn’t accompanied by a headache. It’s just really unsettling. At least now I’ve learned to recognise them and I just try to chill out while it does its thing.
(FWIW, also a tremendous consumer of caffeine here. But this was at 17:00, a good 5 hours after my last cup.)