Why Does Sunlight Make Me Sneeze?

Why Does Sunlight Make Me Sneeze?

by Brian Chou, OD, FAAO, FSLS

  • July 15, 2020


Have you ever noticed yourself or others sneeze when walking out to the bright sunlight?  Up to a third of the population exhibits the “photic sneeze reflex” where the sudden exposure to bright light stimulates sneezing.  First described by Aristotle, researchers still do not understand this phenomenon very well.  Today, it has a clever technical moniker: Autosomal Dominant Compelling Helio-Ophthalmic Outburst, or ACHOO Syndrome.

The Likely Cause of Sunlight Sneezing

At the personal genomics company, 23andMe, researchers have identified at least 54 genetic markers for ACHOO Syndrome.  This means there is a genetic tendency to have it.  A leading hypothesis is that some folks are genetically prone for strong stimulation of the optic nerve to cross over to the adjacent trigeminal nerve, creating the sensation of an irritant in the nose.

Normal Versus Abnormal Light Sensitivity

Although ACHOO Syndrome is not a serious condition and more of a curiosity of physiology – like hiccups, yawning, and snoring – it underscores how light can cause discomfort.  Oftentimes, light sensitivity is normal, and it just means you need a good pair of prescription polarized sunglasses and Transitions light-adjusting lenses.  Yet abnormal causes of light sensitivity have a wide range of causes, from an unhealthy eye surface, infection, inflammation inside the eye, cataracts, susceptibility to ocular migraines, and so forth.  It can also be due to a problematic contact lens causing irritation for those with keratoconus or after corneal transplantation.

The human eye needs adequate light to function well.  But too much light intensity can cause discomfort.  Furthermore, ultraviolet radiation, and possibly blue light, may increase the risk of eye health problems.

To find out whether your light sensitivity is normal or abnormal, request your appointment at ReVision Optometry today.

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