126. sneeze when exposed to bright light!

This condition, known as the photic sneeze reflex, is sometimes referred to as “Autosomal-dominant Compelling Helioophthalmic Outburst Syndrome” (ACHOO Syndrome). The first known mention of this disorder was made back in Ancient Greece by the philosopher Aristotle, who wrote, “Why does the heat of the sun on the nose provoke sneezing?” 

Several centuries later, we are still trying to figure out the mechanism that causes this strange reflex. Sneezes are normally triggered by an irritation in the nose that is detected by the trigeminal nerve. This nerve is rather close to the optic nerve, which senses visual stimuli such as a sudden burst of light from the sun. Scientists believe that when the optic nerve sends an impulse telling the brain to close the eyelids due to bright light, some of the electrical signal is picked up by the trigeminal nerve and mistaken for nasal irritation! Test it and find out - I know that I personally have always wondered why I had this reflex, but it’s kind of fun to be able to make yourself sneeze on comman.