why when sneezing?

Question

why when you are about to sneeze, but it won't come out, you look at something bright and you sneeze???

Answer 1

That is because the optic nerves from each eye travel back toward the brain and meet in what is called the optic chiasm. This optic chiasm lies right next to the nerve that is sending the reflex information to the brain to stimulate a sneeze. The proximity of these two nerves allows impulses traveling down the optic nerve (those associated with the light) to jump across to the nerve transmitting the sneeze reflex. When you have a bright enough light this crossover of neurological stimulation is just enough to put you over the edge and result in a sneeze. There ya go!

And whoever just gave me a thumbs down has the DKS disease. That stands for Don't Know S***!

Answer 2

This has been recognized in medical journals for at least 40 years, and is called different things, including the "photic sneeze reflex" and even the "ACHOO syndrome". In a few instances the reflex has been documented by shining bright lights at people to make them sneeze, so it probably really does happen.
If you shine a light in your eyes, your pupils get smaller, or constrict. You should be able to see this easily in a friend using a flashlight (or in the mirror).
In the pupillary light reflex, shining a light in the eye causes nerve signals to go from the eye to the brain and then back the eye again, telling the pupil to constrict. In the usual sneeze reflex, tickling the nose causes nerve signals to go from the nose to the brain and then back out to the nose, mouth, chest muscles and everything else involved in the actual sneeze. The key point is that the nerve signals take complicated routes through the brain, but usually the pupillary light reflex and sneeze reflex take different routes. Apparently what happens in sun-sneezers is that shining a bright enough light in the eye ALSO sends nerves signals from the eye to the brain and then back out to the nose, mouth and chest! In short, the wires are crossed a little bit in some people, and so shining a light in the eye "accidentally" activates two different outgoing pathways.
This is the best explanation i could find, and i hope it helps.

Answer 3

It's a result of the pupillary light reflex. Basically, when a bright light is shined in people's eyes, it causes nerves to send out signals to constrict the pupil, but in some people, the nerve impulses also cross to the nerves that cause one to sneeze, which is why some people sneeze when they look at the sun or a bright light.

Answer 4

some people look at the light to get rid of a sneeze, but it's something to do with a bright light triggering something in the brain that triggers it.

Answer 5

I don't know but it works. Whenever I look at the sun, I sneeze. Really annoying!

Answer 6

What an interesting question. Here's my guess: As your eyes instinctively squint, that little extra pressure in your facial muscles triggers the sneeze.

Answer 7

for reasons unknown,it is hard-wired into the human physiology to sneeze when staring at bright light .i used to know what it was called-something like "photophobic reaction".i learned it in class,but dont quite remember what it is.

Answer 8

lol that don't ever happen to me ,

so you see a girl that looks bright to you , and you sneeze right at her that would be soooooo funny, really put her off

Answer 9

its the dust particles from the ceiling. when you look up they go right in your nose and you sneeze. lol

Answer 10

it's the easiest way to sneeze!!!! i love it! Why, i don't know??