migraine city

why does my left eye always hurt? i went to the eye doctor and had my vision checked. even after all of these years I still have perfect vision but somehow i have these terrible migraines that come out of nowhere and last for two to three days. i become sensitive to any scent other than lavender oil and bright lights are killer. such as the class that i am currently in, lecture halls are for the birds. the neon lights throbbing through the room, it's difficult for me to even look up away from the computer screen.  i think i need to start wearing some kind of patch.