Scientists are baffled by it, but I'll hazard a guess. I've always thought that the abrupt change from dark to intense light causes the optic nerve, or its buddies, to vibrate. This causes tingles somewhere in my head that radiate to whatever nerve cluster causes a sneeze. At least I think that might be it. But it's only good for two or three good hearty (and I mean honking) sneezes. Maybe four on a good day. But after that, I'm all done. And I can stifle them with sunglasses, or a very conscious effort. But when you've got a talent like this? I let 'em fly. But it's funny. Most times, rather than "achoo," my sneezes almost always come out, "ah-duh-duh-duh-duh-chaaahhhhhhh!" Loud, and stuttery, and really hard to squelch. My step dad's are always like, "Huh-DAH-chuh!" Maybe we all have our own special sneezes?
I'm still dubious about the "up to 35%" of people being affected by photic sneezing though. It always seems to be just me. The best part is that it's called "ACHOO." That's Autosomal Dominant Compelling Helioophthalmic Outburst (yeah, they kinda cheated).
Read more about Photic Sneezing at: Wikipedia
Latest research suggests a lower percentage.
ReplyDeleteHere's an interview with the leading specialist on the question, Lois Ptacek, who admits that no one really knows the prevalence of the reflex, but he puts it at about 10%
http://www.mrscienceshow.com/2010/08/ep-135-why-do-i-sneeze-at-sun.html?utm_medium=bt.io-twitter&utm_source=direct-bt.io&utm_content=backtype-tweetcount
Thanks for visiting. But the one thing I've always wondered: is it weird to LIKE to sneeze? I kinda get a kick out of it. I don't squelch them unless I'm in a situation where the sound would be disruptive. Otherwise? Ba-Ba-Guh-Ghhhhha-Ba-Ba-Ba-CHOOOOOOOOOOO!!!!!!!! A good sneeze can be almost as good as a good poo. And THAT should tell you that I'm entering that area between adult and MIDDLE AGED.
ReplyDeleteI suppose it's enjoyable if it doesn't happen too often. I'm pretty sensitive to strong light, and it can be really dangerous if it happens when you are driving.
ReplyDeleteMartin
I read somewhere that the reflex is more common in people of Nordic descent. Since Las Vegas has a large Hispanic population, that may explain why it seems like you're the only one sneezing at the sun. Maybe it evolved so that our ancestors would clean out their sinuses when they were outside the longhouse, instead of infecting everyone inside.
ReplyDeleteGreat hypothosis, Jill! Almost my entire family can be traced to England, Ireland, Scotland, Holland. . .you know, damp and/or cold European countries. I'm so pale, I'm almost transluscent. Maybe mother nature figures, I naturally look sickly, so I should sound like it too?
ReplyDeleteJames, can I ask a question ?
ReplyDeleteCan you actually demonstrate the photic sneeze reflex ?
If someone asks you what it is, can you say "Well I'll show you!", go to the window and look out... and Bingo !
I can about 80% of the time, and it doesn't even need to be particularly sunny, so long as I look up at the light with the right angle.
Martin
Martin,
ReplyDeleteYes, I can demonstrate it, probably with a higher than 80% rate. More like 97%. Once in a while, a sneeze will get "stuck," but I can usually rattle off two or three, sometimes four. Then, I have to go into the shade to "reload!"
The bad part is, with the glare in Las Vegas, they're usually big foghorn sneezes that CAN'T be squelched. Very noisy, probably obnoxious.
97% success rate ! That’s very impressive. I tried to look out of the window, but it’s too dull and overcast. I can feel the neurons firing as I look up into the sky, but it’s not quite enough to actually bring it off.
ReplyDeleteI realize now that the reflex works differently for me if I try to force it, or if it happens by chance, without me expecting it.
For example, if I’m driving and the sun suddenly comes out from behind a cloud and hits my eyes at a certain angle, the reflex is fired almost immediately – only five to ten seconds between the light hitting the eyes and the first sneeze. But if I want to show someone how the reflex works, by actively looking up at a source of light, it takes at least 30 seconds or even a good minute before the reflex is actually set off. And then there are only the statutory two sneezes. If it takes me by surprise, there are usually half a dozen.
Have you ever noticed a difference ?
Martin
Maybe a little. It's difficult if I'm on the edge of a sneeze already, and then try to force it with the sun. If I'm caught off guard, yes, it's almost immediate. I guess if I try to "make" a sneeze, I've got to find the right angle to catch the glare, so it might take longer. But yeah, my "success" rate is somewhere near 100% with the sun. With other sources of light, it's way lower.
ReplyDeleteThanks, James, all very interesting.
ReplyDeleteThe photic sneeze reflex is fascinating for those of us who have it, but probably very boring for everyone else.
As you are obviously a true photic sneezer, you might be interested in doing Dr Ptacek's questionnaire
http://www.newscientist.com/data/doc/article/dn16959/photicsneeze.pdf
I did it when it came out, and I think it's still a current project. You will probably find that you can't answer all the questions straight away, and you'll need to observe yourself for a few weeks.
It's to be sent back to ucfsneezesurvey@googlemail.com
Martin