Thank you both.
Hyphen, my cluster headache came after the aura went away. I'm sorry to hear that you've experienced this since childhood. I can't imagine having something like this happen as a child! It was scary. I didn't know if I would be able to see again. I'm divorced and was home alone with my 9 year old. Not a good feeling.
CHfather, I am definitely going to read the study. It sounds interesting. Thanks for the suggestion.
It hasn't happened since. I'm hoping it was a one time only thing. A friend suggested dehydration.
Few interesting things to add to the quest for answers.
1. My brother also get clusters, chronically like me.
2. A few years ago I went for an eye exam. Once my eyes were dilated I was unable to focus the eye on my cluster side. I couldn't even make out the largest letters.
Have any studies been done to see if there is an increase of cerebral spinal fluid at the base of the brain?