Imponderable of the Day: Why Does Looking at the Sun Make You Sneeze?

It’s a very curious sensation: You’re inside a dark room for a bit too long and when you step back outside into the bright sunlight, you suddenly feel a sneezing fit coming on. What’s the deal?

Staring at the sun makes about 20 to 35 percent of humans sneeze, and although scientists have a general idea of what causes this sensation, it’s still a very confusing conundrum. The phenomenon, which is known as “photic sneeze reflex,” is actually a genetic trait, which is why it only affects a small percentage of people. These people have visual systems that are more sensitive than those of other people, causing them to become agitated by the sunlight and send panicked responses to all of the nerves in the face, including the somatosensory system, which controls sneezing!

Now, go ahead and impress your friends with this new tidbit of information!

Looking at the Sun Can Trigger a Sneeze [Scientific American]
Why does bright light cause some people to sneeze? [Scientific American]
Does the sun make you sneeze? It's not just you [NBC News]
How Staring at the Sun Can Make You Sneeze [Gizmodo]