Have you ever needed to sneeze, but just couldn’t? Has someone ever told you to look into a light to make yourself sneeze? For some of you, it may have worked. But why?

Why does light cause sneezes?

Up to a third of the population can trigger sneezes by looking at a light. This reaction has two names: the first is the photic sneeze reflex, or PSR. The second is ACHOO syndrome. ACHOO stands for autosomal dominant compulsive helio-ophthalmic outbursts of sneezing.

While scientists aren’t certain what causes this reaction, it is believed to be caused in part by the optic nerve’s closeness to the nerve responsible for facial sensation and movements. This nerve is called the trigeminal nerve. When the optic nerve senses sudden bright light, it constricts the eye’s pupils. For those with ACHOO syndrome, doctors believe this signal is misinterpreted by the trigeminal nerve, causing a sneeze.

Can this reaction ever be a problem?

This can be very convenient for people who need to sneeze but just can’t, but there are more serious implications to consider. People with this condition might find themselves overcome by sneezing if they were suddenly hit with bright light while driving. People’s eyes close tight when they sneeze, which means they would temporarily lose their vision. This has also been a concern for pilots.

Michael Sicard, MD

Fortunately, ACHOO is triggered just by bright light, not by any specific wavelengths of light. Therefore, a simple pair of sunglasses can prevent this reaction.

Also, you don’t want to make yourself sneeze too much.

“While a sneeze denied is frustrating, recurring fits of sneezing are an unwelcome and even dangerous purge of nasal irritation,” CEENTA ENT doctor Michael Sicard, MD, said.

Remember, if you ever have concerns about how much you’re sneezing, CEENTA’s ENT doctors are available to you.

This blog is for informational purposes only. For specific medical questions, please consult your physician. Dr. Sicard practices in our Matthews office. To make an appointment with him or any of CEENTA’s ENT doctors, call 704-295-3000. You can also request an appointment online or through myCEENTAchart.


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