It is more about signal leakage between neurones. The optical nerve is closed to the one controlling sneezing so when the optical is highly excited, it can activate the sneezing nerve.
Source : I have a friend with this and he looked it up once
That’s the prevailing theory, yes, but as far as I’ve found there’s not empirical evidence to back it up. The theory does make perfect sense to me, though!
Also, as a sufferer, I’ve noticed it almost always requires sunlight or something with close to the same frequencies. Most artificial lights don’t trigger it *for me.
Artificial lights absolutely trigger it for me. They just have to be bright.
“Bright” is kind of a spectrum though. Sometimes a light is just bright enough that you can trigger a sneeze, but only if you focus on it. Other times that same light will almost trigger a sneeze with focus, but not go completely over the edge. That’s a very annoying feeling when that happens.
Interesting! I’ll update my post, it makes sense there would likely be variability in how it presents due to biology. My experience isn’t necessarily the default.
I have this and it’s annoying but has the best name.
It’s known as ACHOO syndrome. Autosomal Dominant Compelling Helioopthalmic Outburst.
Contrived acronym. I much prefer Photic Sneeze Reflex, it’s easier to remember and doesn’t sound like bullshit 😂
I have no research to back this up, but I think it’s just a glitch that isn’t detrimental to passing on one’s genes, so the trait got to stay around. Not everyone has it.
But if I were to hypothesize an evolutionary benefit, maybe it is a good thing to sneeze out all the fungal spores from your cave once you emerge. But then again, if it was important, shouldn’t this also induce coughing?
Not every trait has an adaptive significance.
I always assumed it was a hold over from a rodent-like ancestor. Stick your nose out of a barrow, and you want to clear it to get a good sniff of the environment.
It’s definitely one of those effects that confuses people. If you don’t do it, it seems weird as hell. If you do, it seems weird that some people don’t get it.
Closes your eyes when you stare at the sun?
No! I will burn out my retina and there’s nothing you and big sunglass can do to convince me otherwise!
Wait what? I don’t recall doing this. Or do you mean squinting instead of actually sneezing?
No, sneezing, as in the photic sneeze reflex. If I look at the sun by accident I’ll sneeze.