Useless fact
Why do some people sneeze when looking at the sun?
The genetic trait that causes people to sneeze when suddenly exposed to bright light is called the photic sneeze reflex.
The photic sneeze reflex, also known as autosomal dominant compelling helio-ophthalmic outburst syndrome, is a benign genetic condition that affects roughly eighteen to thirty-five percent of the global population. When a susceptible individual moves from a dark environment into bright sunlight, they experience an uncontrollable urge to sneeze. Researchers believe this occurs because of a mix-up in the cranial nerves, specifically where the optic nerve, which detects bright light, stimulates the trigeminal nerve, which manages nasal irritation. While this trait was first documented by the ancient Greek philosopher Aristotle, modern scientific investigation has established its hereditary nature. It is inherited in an autosomal dominant pattern, meaning a child has a fifty percent chance of inheriting the reflex if one parent has it. Although harmless in everyday life, this reflex can present sudden hazards for people in certain high-concentration professions, such as fighter pilots or drivers exiting dark tunnels.
Why this is true — The photic sneeze reflex is a recognized genetic trait cataloged in the MedlinePlus and NCBI databases as a response to sudden bright light.
Sources
- Photic Sneeze Reflex National Center for Biotechnology Information