Always wondered this....?

Question

When I look up at the sun really quick...not on purpose, I always sneeze. Am I allergic to the sun??

Answer 1

Dave B is right. It's called the "photic sneeze reflex."

"Photic sneeze reflex (also referred to as sun sneezing, photogenic sneezing, or whimsically called ACHOO, a backronym for Autosomal dominant Compelling Helio-Ophthalmic Outburst) is a medical condition by which people exposed to bright light sneeze. The photic sneeze reflex can also cause one to sneeze many times consecutively. The condition occurs in 17% to 25% of humans with more common occurrence in Caucasians than other human races. The condition is passed along genetically as an autosomal dominant trait.

The first mention of the phenomenon is probably in the later work attributed to Aristotle (Problems, book XXXIII).

The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus. The fifth cranial nerve, called the trigeminal nerve, is apparently responsible for sneezes. Research suggests that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneeze reflex. Another theory suggests that tears leaking into the nose through the nasolacrimal duct are a cause of the photic sneeze reflex. The speed of the reflex seems to favour the first theory, as it happens much too quickly for tears to be generated and drain into the nose. In addition this sneeze reflex can be brought on by a sudden inhaling of cold air or a strong flavor such as a strong mint gum. This implies an overstimulation of any nerve close to the trigeminal nerve can cause the sneeze reflex."

Answer 2

Mate, if you were allergic to the sun you'd either:

1. look like me

2. be really friggin miserable all the time

3. be dead

yer not allergic to the sun, as to why you sneeze it beats me, neurological reaction perhaps?

Answer 3

No. You and I are part of the estimated 20% of humans that have a sinus reaction to bright light. It can be embarrassing but not harmful.

Answer 4

Hmmm... I think ... that you can only be truly allergic to things that contain proteins... the other things are sensitivities and not true allergies.

Answer 5

not true... you can't be allergic to the sun. you cant be allergic to a big ball of fire.

Answer 6

actually, you got it the other way around.
when you're out, and you wanna sneeze, getting ready to sneeze, you just happen to look up...

Answer 7

Yes. You must move offworld immediately. A spaceship will be sent to your coordinates immediately.