Genetics in a Sneeze
When you look at a bright light and start sneezing, the cause is a genetic reflex called Autosomal Dominant Compelling Helio-Ophthalmic Outburst Syndrome, also known by the acronym ACHOO. It is estimated that 20– 35% of the human population has the “photic sneeze reflex” or a “solar sneeze” trait. To test if you have the gene, go into a dark room and wait for your eyes to adjust to the darkness. Then exit the room and look at a bright light, preferably the sun. Most people will sneeze 2– 3 times when the reflex is set off.