The anatomy of a sneeze is pretty disgusting. For someone with a cold, allergies, or just a tickle in the nose, it takes less than a second to eject about 5000 droplets of mucus from their nostrils at speeds of up to 100 mph. Those infectious snot particles can travel up to nearly 30 feet and remain suspended in the air for up to 10 minutes, creating a plume of biohazard air that threatens anyone in its path.
Our body doesn't mind delivering germs at high velocity, but it does appear to dislike looking at it. During a sneeze, most everyone involuntarily closes his or her eyes as a reflex action. Why? And what happens if we try to keep them open?
“Part of the sneeze reflex involves muscles in the eyelid region,” says Dale Tylor, MD, a pediatric and general otolaryngologist at the Washington Township Medical Foundation in Fremont, California. “I would be speculating, but likely it doesn't make sense to have your eyes open when you have these tens of thousands of microparticles coming out at high speeds from your nose, because then they could possibly get in your eyes.”
Tylor is quick to add that scenario isn't science—we really don’t have a definitive answer as to why we close the eyes, just an educated guess based on what we think our body is trying to defend itself from. Namely, snot.
Some people, however, can keep their eyes open during a sneeze, like the young woman who thoughtfully captured this feat on video. (Warning: though not graphic, it’s very odd to see someone sneezing and making eye contact.)
People this talented are rare, according to Tylor. And any urban legend about “blowing out” your eyes if they happen to be open while sneezing is not really possible. Still, while you could try to sneeze with your eyes open, it’s best to let your body do what it does best: protect you from your own disgusting functions.