Sneezing In The Sunlight
Nobody really knows why many people sneeze when they go into the sunshine. It’s called photic sneezing and there is a theory that could be the explanation for what happens. The optic nerve is the nerve responsible for contracting the pupils of the eyes in bright light, and the trigeminal nerve which is responsible for sneezing is quite close to the optic nerve. So the theory is that the optic nerve somehow sets off the trigeminal nerve.
The thing that makes sneezing provoked by sunlight is not entirely connected to the embarrassment it may cause. It’s physically impossible to sneeze with your eyes open, so if you get an attack of sneezing when you are driving a car or flying a plane, you could be in big trouble.