Does Bright Light Make You Sneeze?

There hasn't been a lot of research done to determine why some people sneeze when they are exposed to bright light. This condition is known as photic sneezing, which is genetically linked. I have been a photic sneezer for as long as I can remember.

Scientific American explains:

“The trait is autosomal-dominant. The gene is neither on the X nor Y chromosome and only one copy of the gene has to be present for the trait to be expressed, so if one parent sneezes when they look at a bright light, about half of his or her children will, too.”

A study on photic sneezing was published in the Archives of the Spanish Society of Ophthalmology. There were only 12 people in the study and all of them were members of the same family, so the researchers acknowledged that other research might be warranted.

Photic sneezing is much easier to remember than the scientific name for this condition which is autosomal dominant compelling helio-ophthalmic outburst syndrome. Believe it or not, this syndrome is referred to by the acronym ACHOOs, which occurs only at the onset of the appearance of a bright light, not continually as you remain in the bright light.

One theory is that photic sneezing may have something to do with thicker than average corneal nerves, since 2/3 with this syndrome have this in common.

Researchers in a study undertaken in Israel in 1990, found that individuals with photic sneezing have above average intelligence.

Photic sneezing seems to be much lower with white females, as compared to white males, but that statistic appears to be completely unrelated to the intelligence of the genders.

A quote from BBC, explains a theory of the science behind photic sneezing:

“A sneeze is usually triggered by an irritation in the nose, which is sensed by the trigeminal nerve, a cranial nerve responsible for facial sensation and motor control. This nerve is in close proximity to the optic nerve, which senses, for example, a sudden flood of light entering the retina. As the optic nerve fires to signal the brain to constrict the pupils, the theory goes, some of the electrical signal is sensed by the trigeminal nerve and mistaken by the brain as an irritant in the nose. Hence, a sneeze.”

There is no known cure for or treatment of photic sneezing, which also isn't considered a pathology.

Fortunately, wearing sunglasses largely eliminates photic sneezing for aircraft pilots.

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