Question 1

Why does bright light make some people sneeze?

Accepted Answer

Bright light triggers sneezing in people with the photic sneeze reflex, an inherited trait. EEG studies show their visual cortex responds more strongly to sudden light, and that excess signal spills into nearby brain circuitry and gets read as a nasal irritation, producing a sneeze.

Question 2

What is ACHOO syndrome?

Accepted Answer

ACHOO stands for Autosomal Dominant Compelling Helio-Ophthalmic Outburst syndrome, the medical name for sneezing in response to bright light. It affects roughly a quarter of people and is inherited: if one parent has it, each child has about a fifty percent chance of carrying it too.

Question 3

Is the photic sneeze reflex genetic?

Accepted Answer

Yes. It follows an autosomal dominant inheritance pattern, meaning one copy of the responsible variant is enough. A 2010 genome study linked the trait to a common genetic variant called rs10427255, confirming what family studies had suggested decades earlier.

human-biology

All essays in .

The Sneeze That Begins Behind Your Eyes

The Slowest Predator on the Savanna

The Mutation in Your Coffee Cup