Here's something most people don't know about me... my whole life I've sneezed when I look at the sun or bright light. Heard of people here and there with the same thing, but for the most part, people (even Doug) thought it was kind of strange. Well, we discovered the answer one day when playing Trivial Pursuit:
Autosomal Dominant Compelling Helio-Ophthalmic Outburst Syndrome
Also known as ACHOO syndrome (ironic, I know) or a Photic Sneeze Reflex
It occurs in about 17% - 25% of the population. I didn't really look anything up on it until I noticed Carson does the same thing. Come to find out it is genetic. How about that?
More at
http://en.wikipedia.org/wiki/Photic_sneeze_reflex