wikipedia wrote:
Photic sneeze reflex is a genetic autosomal dominant trait, which causes sneezing when exposed suddenly to bright light, possibly many times consecutively. It is also referred to as photic sneeze response, sun sneezing, photogenic sneezing, the photosternutatory reflex, being photo sensitive, ACHOO syndrome, and "Achooism," with its related backronym Autosomal dominant Compelling Helio-Ophthalmic Outburst syndrome. The condition affects 17 to 35 percent of humans.
I do this, too so I had to look it up.