why does looking at the sun make you sneeze?

Answer 1

If you sneeze when looking at a light, you are not alone! As many as one out of every three people seem to have this interesting phenomenon, called photic sneeze, in which bright light triggers a sneeze. Sir Francis Bacon even wrote about it, almost 400 years ago, "Looking against the Sunne, doth induce Sneezing."

We generally sneeze to get rid of something that is irritating the inside of our nose, such as dust, pollen, or viruses. The body uses lots of nerves and muscles to coordinate this protective reflex. Although no one knows exactly why photic sneezes happen, there are some theories. A popular one is that a sudden flash of bright light causes the nerve signal leaving the eye (along the optic nerve) to trigger a nearby nerve (trigeminal) that goes to the nose, thereby causing a sneeze. Another theory suggests that bright light causes the eye to make more tears, which drip into the nose and trigger a sneeze.

Answer 2

It's a genetic thing that doesn't happen to everybody. It's called "photic sneeze reflex". Very interesting. (I do it---nobody else I know does.) It isn't really looking at the sun that usually causes it, but going into bright light after being in a darker place. That's why you often notice it when you go out of a building into the bright daylight.

http://www.ucsf.edu/humgene/photic_sneeze_reflex.htm

http://www.dankarran.com/sunsneezing/

http://www.straightdope.com/classics/a2_303.html

Answer 3

It's not looking at the sun, it's the tilting of your head up that does it. You can get the same effect by looking up at overhead lights in a room. And that only works if you have to sneeze but you can't.

For me I don't actually sneeze, but the urge to goes away.

Answer 4

I've heard this question before. I'm gonna go out right now and look at the sun and see if it makes me sneeze, because I have never experienced this. I'll let you know.

OJ, I;n badj. No smeexing, but noe I cam;r SEE. Thamls for thr suffestuib!

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Answer 5

I've always wondered that. Happens to me all the time!