why are some people compelled to sneeze when exposed to intense light?

Question

This happens to me, and some others I know, but not everyone.

Answer 1

well, without tests one can only guess. Intense light has an effect on the whole body, not just the skin. Certain vitamins are created by exposure to sun light.
Intense sun light might be causing some sort of an allergy, which translates in your case into sneezing, others itching.