Why do some people sneeze in the sun?

I thought everyone sneezed when they walked out of a building into the bright sun. But it turns out only one in ten people have the genetic condition called "photic sneeze reflex." In this video, we learn more about photic sneeze reflex and why some of us sneeze in the sun. The current hypothesis is that the brain of people who have photic sneeze reflex misinterprets bright light as an irritant in the nose, which triggers a sneeze.