Photic Sneeze Reflex?

[joshquintanilla]

Photic sneeze reflex: A disorder characterized by nearly uncontrollable paroxysms of sneezing provoked in a reflex fashion by the sudden exposure of a dark-adapted subject to intensely bright light, usually to brilliant sunlight. The number of successive sneezes is usually two or three, but can be up to about 40.

Any ideas about why a quarter of the population has this reflex? Why would we adapt to have this? Maybe a lack of sun exposure during childhood makes us more sensitive to sudden exposure and causes sneezing of all things?

 

[opethfeldt]

Photic sneeze reflex: A disorder characterized by nearly uncontrollable paroxysms of sneezing provoked in a reflex fashion by the sudden exposure of a dark-adapted subject to intensely bright light, usually to brilliant sunlight. The number of successive sneezes is usually two or three, but can be up to about 40.

Any ideas about why a quarter of the population has this reflex? Why would we adapt to have this? Maybe a lack of sun exposure during childhood makes us more sensitive to sudden exposure and causes sneezing of all things?

The lack of sun is definitely true in my case. I reliably sneeze in directly sunlight and I was in darkness most of my childhood.