Why does looking up at some source of light help you sneeze?
370361
Probably because your face contorts (even if only slightly when the light source is mild), and that adds to the irritation in your nostril, triggering off a sneeze.
406470
Wow. I don't believe someone asked this.\nMy ex-husband had this problem everytime he went outside.\nIt was years before a doctor didn't look at him like he was nuts and gave him a real answer.\n\nApparently there is a nerve that runs across the bridge of the nose.  In most people it is located such that there is no problem.  In other people the nerve is only millimeters in a different location.\n\nWhen he went out into the sun the squinting of his eyes due to the sudden increase in light irritated that nerve and caused a sneeze reaction.\n\nHope that helps.  My ex is still nuts, but that's another story! lol
462099
Because it makes your sinuses start running from the sudden heat.\nYou're not allergic to sunshine, I thought that kinda thing too and asked my doctor and he just said it's the heat making your sinuses run, so you sneeze.
376593
No one knows the reason you close your eyes when you sneeze. There are many possibilities.  the reason held by most doctors is that closing your eyes when you sneeze is a reflex and it's very difficult to change that.  Actually when you sneeze the velocity at which the air comes out is about 99 mph.   During this part of the sneeze, we tense some of our facial muscles an d by doing this tensing (tightening) of our muscles causes our eyes to shut. therefore, i think that closing your eyes is just part of the reflex of sneezing.
475713
It doesn't do that with everyone....\n\nbut in most people the nerve from the eye (Optic nerve) runs just next to the nerve for the nose(Olfactory nerve).\n\nSo a powerful light stimulate the optic nerve, which stimulates the Olfactory nerve (from proximity) - the result is a feeling that you need to sneeze.\n\n\n-- edit --\nWhoops.. not the olfactory nerve- that conveys odors...\n\nHere is a snip from a web page addressing this issue:\n\nQ. Why Does Sunlight Cause Sneezing?\nFrom Apply Now, Your Guide to Vision.\n\nUp to 25% of us can't escape it. We walk out of a dark movie theater into the bright sunlight, and then it happens: "Ah choo!" This sneeze reflex is a genuine phenomenon. So what causes it? \n\nA. Close association between the eye’s optic nerve and nerves causing the sneeze reflex may explain why an estimated 5-25% of people sneeze with sudden exposure to bright sunlight or other light sources.\n\nSudden bright stimulation of the eye that occurs after a person has become adapted to darker surroundings is thought to bring on the condition, known as photic sneeze reflex. The reflex also is called Autosomal Dominant Compelling Helioophthalmic Outburst Syndrome, known by the acronym ACHOO. (Not making this up. Really.)
870320
ditto to the 2 answers above\n\nyou may get some peace from sneezing ect ... because you are relaxed\nbut you still CAN sneeze
72870
Sounds to me like you've got a condition called photic sneeze reflex.
123908
I have no idea why, but looking at a bright light (such as the sun) usually works.
381936
It is called a photic sneeze reflex.  It is believed the overstimulation of the optic nerve triggers a sneeze via a malfunction in nerve signals.
381087
I read about this.  It happens in bright light because the optical and nasal nerves are so close together.  The brain is receiving all these signals from both that are so close together that it can sort of trick itself.
330018
Photic sneeze reflex (also whimsically called ACHOO, a backronym for Autosomal dominant Compelling Helio-Ophthalmic Outburst) is a medical condition by which people exposed to bright light sneeze. It has been suggested that the photic sneeze reflex occurs only after someone has been adapted to the dark for at least five minutes, although this is not certain, and is not uniform amongst people with the photic sneeze reflex. 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.\n\nThe first mention of the phenomenon is probably in the later work attributed to Aristotle (Problems, book XXXIII).\n\nThe 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 inhailing 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.
422229
When you sneeze the air from your nostrils come out with great force (infact stronger than the strongest wind!).\n\nIt is said that if you sneeze with your eyes open, your eyeballs might pop out!! It may be possible as our eyeballs are just held in sockets and do not have supportive structures to hold them in place.\n\nWhen you try to hold back a sneeze, your eyes start watering a little bit.
951717
Look at a brihgt light until you sneeze. Or Get some pepper and smell deep into it if you wait a while.\n~*Alyssa*~
178849
The actual reason is to combat the pressure build up in your sinuses. \nSneezing releases alot of force.\nYour eyes are linked to your sinuses, and well - you wouldn't want to blast them out of your head now would you?
320133
Not an expert, but it seems to be a kind of reflex action in a small percentage of people. If you experience the "sun sneeze" the same way that I do, it only occurs if I look skyward or toward the bright light of the sun.  If  I look away, I lose the urge to sneeze.  My best guess is that it may be a crossed wire of sorts in some people where an overload of the visual senses creates a reaction.  Since it is impossible to keep your eyes open during a sneeze, it could be that this reaction is the body's attempt to protect your eyes from exposure to the intense light.
813273
Yes it does.  My eyes squint, my nose starts itching, and then I sneeze. I thought I was the only one who did that.
309689
it helps prevent (doesnt completely block) the germs from flying over the entire room or onto other people around you, but do know that if you dont wash your hands right after sneezing you are spreading the germs that are then on your hand.  it is reccomended to sneeze into a tissue or a handkerchief to prevent the spreading of germs.