If You Sneeze When You See Bright Light, There's a Reason

by N/A, 10 years ago | 2 min read

ACHOO! Yes, that's the sound you make when sneezing, but it also stands for exactly what's happening at the time: autosomal dominant compulsive helio-ophthalmic outbursts of sneezing is a syndrome of sneezing set off by light. This is also known as another acronym: PSRâ€“photic sneeze reflex.

Okay, so that's a lot of big words and jargon, but a PSR is something that shouldn't be taken lightly, because of, well, light. Heightened sensitivity could prove to be problematic in everyday life.

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17 to 35% of the population is prone to PSR, which can be traced back to the brain.

You see, the brain is in chargeÂ trigeminal nerve, which is responsible for your face's sensation of movement and detects irritants. Just like if there is hair or dust in your nose, when transition from dim to bright light, your eyes constrict the pupils, however that signal is misinterpreted and a sneeze results.

So, a sneeze can be set off by any light, but especially the sun. In fact, Francis Bacon tested a theory that it was the heat of the sun that caused tears, even when your eyes were close, to trickle down into the nostril and irritate it.

Although this isn't exactly the truth, the theory isn't that far off. Because, it is irritants that cause a sneeze.

If you're prone to PSR it's likely your parents had this condition. The chromosome is autosomal-dominant, meaning it only takes one copy of the gene for the trait to be expressed.

So, if a parent has it, there's a 50/50 chance their offspring will have it too. But, PSR is not just an everyday annoyance. It can have some serious implications for your safety, considering it's such an unplanned occurrence.

Consider this: you suffer from PSR and are driving through a dark tunnel. As you near the exit of it, the bright light comes shining into your eyes, and without any hesitation you heavily sneeze...

Sounds like a car accident waiting to happen. It's it not just a safety hazard for drivers. The momentary loss in vision can be bad news for tightrope walkers, outdoor athletes and even pilots. Fortunately, a study done back in 1993 shows that simply wearing sunglasses can help prevent this from happening.Â

So, that's how baseball players manage to catch those pop-flies without sneezing their brains out? Yup.

So, now you know why the light is always making you do this...

Maybe now you can better prepare yourself for the impending: ACHOO!