I think I'm much like Karen. Had massive problems with migraines this past summer, being a expedition sea kayaking guide and paddling 5 to 8 hours a day meant high levels of exposure to sun glare. Even with polarized expensive sunglasses and a big hat I would get them. My migraines are crazy painful and make me throw up every 10 minutes for 5 hours or so.
My migraines seemed to be tied to sun glare but I was also eating TONS of carbs like 200+ g/day due to the limiting factors of eating on expeditions. Try eat paleo for a 5 day trip on which you must- fit everything in a kayak, you can only cook dinner- breakfast and lunch are open and eat, and of course it's 95+ degrees out and no refrigeration. pretty tough. Needless to say I ate lots of processed foods and lots of grains.
The weird thing is that I didn't have any problems the previous summer doing the exact same thing and eating the exact same foods. I don't know if there was some sort of hormone change or what.
Since going paleo, I've only had one migraine which I tied to dehydration and killed with lots of painkillers but I haven't spent long days exposed to high levels of sun glare. I'm curious to see if I still get migraines on a kayaking trip while eating paleo.
Also, I have blue eyes.