Me too - it's called Photic Sneezing.

From the WikiPedia entry:

The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus. The fifth cranial nerve, called the trigeminal nerve, is apparently responsible for sneezes. Research suggests that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneeze reflex.

I also sense in bright light, and find that I have to don sunglasses earlier than others, but conversely I also seem to have much better night vision than many people... Could it be that there is also an advantage to high optic nerve senstivity?