because your eyes took in too much light all of a sudden, because of a tall cup of coffee (caffeine stops some migraines but makes others), menstruation, a chocolate bar (maybe), a glass of red wine or a glass of white, cigarette smoke, air travel, that storm front coming down from Denver, the leaves falling off the big oak in your front yard, that extra hour of sleep you got last night, the hour of sleep you lost, too much heat, too little water, too much stress or too little, that other headache, the painkiller you took to stop the last migraine, the last migraine itself, your Eastern
...more
