Why does looking at a bright light or sunlight sometimes make people sneeze?

Discover ^ | January 2002 | Louis Ptacek

[Oxylus]

Question:
Why does looking at a bright light or sunlight sometimes make people sneeze?

Carl Owens,
Corcoran, California

Louis Ptacek of the University of Utah's Howard Hughes Medical Institute replies:

Sneezing provoked by sudden exposure to intensely bright light is known as the photic sneeze reflex. It is not uncommon'about one in 10 people are photic sneezers. Some studies suggest it may be due to an accidental crossing of nerve signals involved in normal sneezing and pupil dilation. But the photic sneeze reflex occurs only after someone has been adapted to the dark for at least five minutes. Even photic sneezers' pupils will adjust normally (without triggering a sneeze) if they go in and out of bright light for short periods of time, so the real mystery is why an extended period of darkness makes a difference. The reflex is not troublesome to most people, but it is of considerable interest to scientists. The trait travels in families'approximately 50 percent of children born to photic sneezers are photic sneezers themselves'so it should be possible to identify one or more genes that are responsible. The photic sneeze reflex may also relate to other reflex phenomena. For example, people with epilepsy frequently have seizures induced by strobe lights, and visual stimuli can precipitate headaches in many migraine patients. Studying the photic sneeze reflex is likely to improve our understanding of sensory pathways in the nervous system, as well as the circuitry of the sneezing reflex.

[Cobra64]

I think it's also hereditary since both my son and I have this condition. Sometimes, when I'm on the brink of sneezing, I look at a light, and it fires off a good sneeze.... and yes, I cover my nose!

[Capt. Tom]

dang...this is a first. I yawned by READING the word Yawn!?!

I'm a photic sneezer and rarely yawn but like you, after reading about yawning I found myself yawning. That feels great just had a few more yawns. -Tom

[blam]

"I wasn't aware of this phenomenon but I wanna know why yawning is catching."

Don't know. However, the sea horse is the only animal to never have been observed yawning.

[SteamshipTime]

Thanks for sharing.

[des]

This works to squelch a sneeze. It's peculiar that the same reflex causes sneezing in others.

[Sabertooth]

(((ping))))

[Marie Antoinette]

BGH - You photic sneezer, you!

I hereby apologize for poking fun at your multiple sneeze fits every time we go outside :-)

listenhillary, are you photic as well?

[AnnaZ]

I've never notice that exposure to light makes me sneeze. OTOH, when I feel a sneeze coming on but am tortured because it won't materialize, I was taught to look at a bright light or the sun to bring the sneeze on. Sure enought, it works every time!

That's me, to a T!

[an amused spectator]

LOL! Beat me to it. ;-)

[Bob]

dang...this is a first. I yawned by READING the word Yawn!?!

I don't know how many others may have, but I did too.

[RJS1950]

The sunlight in some people, triggers an IGg cascade causing a an allergic reaction (sneeze).

[SpottedBeaver]

No...

Boing! :)

[aruanan]

But the photic sneeze reflex occurs only after someone has been adapted to the dark for at least five minutes.

Yeah, right. If I feel the least little bit like a sneeze could possibly be there, a look at a light is enough to do it several times, no dark adaptation needed. Personally, I think it's a cross circuit between the optic and orgazmo nerves.

[aruanan]

One who sneezes on exposure to bright light, and breaks wind while he sneezes, is said to have photic-phartic sneeze reflex.

Isn't that the snooter/pooter reflex?

[mykdsmom]

How about Snooter/Tooter.

At least that is what I try to get my boys to call it...........they like the word FART better.

Usually at the top of their lungs, and in public. Must be a guy thing : )

MKM

[BansheeBill]

The post-coital phase of orgasm sometime causes me to sneeze....

Excuse me but I think you are referring to "pubic sneezing".

This thread is about "photic sneezing".

[mykdsmom]

Man what a sucky job...sitting around waiting for animals to yawn.

Why do they even know this?.......Now I'm even more confused.

They can study animal yawning habits but can't explain why I'm yawning repeatedly right now just typing about yawning.

MKM

[d4now]

fyi

[SlightOfTongue]

Nothing personal, but...

We must really be 'scraping the bottom' for threads when these kind show up. Either that, or some people have absolutely nothing to do, and all day to do it.

[monkeyshine]

I think I may be one of these photic sneeze relfexers. Not every time I go into the sunlight, but on occasion.