Autosomal dominant Compelling Helio-Ophthalmic Outburst (ACHOO)
why do some people sneeze in the sun?
it's about 1/4 people, supposedly that does.
it's sometimes called "Photic sneeze reflex" or ACHOO syndrome (that pretentious punny acronym in the subject line: Autosomal dominant Compelling Helio-Ophthalmic Outburst) that's quite a mouthful.
http://www.photic-sneezing.fr.st/
"The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus."
http://www.madsci.org/posts/archives/aug97/865380242.Me.r.html
"one of the bodies reflexes is the "pupillary light reflex". If you shine a light in your eyes, your pupils get smaller, or constrict.
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."
Aristotle had it:
"In Book XXXIII, in a section entitled 'Problems concerning the nose,' Aristotle stated: 'Why is it that one sneezes more after one has looked at the sun? Is it because the sun engenders heat and so causes movement, just as does tickling the nose with a feather? For both have the same effect; by setting up movement they cause heat and create breath more quickly from the moisture; and it is the escape of this breath which causes sneezing."
apparantly, i am a "Compulsive Photic Sneezer"
it's about 1/4 people, supposedly that does.
it's sometimes called "Photic sneeze reflex" or ACHOO syndrome (that pretentious punny acronym in the subject line: Autosomal dominant Compelling Helio-Ophthalmic Outburst) that's quite a mouthful.
http://www.photic-sneezing.fr.st/
"The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus."
http://www.madsci.org/posts/archives/aug97/865380242.Me.r.html
"one of the bodies reflexes is the "pupillary light reflex". If you shine a light in your eyes, your pupils get smaller, or constrict.
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."
Aristotle had it:
"In Book XXXIII, in a section entitled 'Problems concerning the nose,' Aristotle stated: 'Why is it that one sneezes more after one has looked at the sun? Is it because the sun engenders heat and so causes movement, just as does tickling the nose with a feather? For both have the same effect; by setting up movement they cause heat and create breath more quickly from the moisture; and it is the escape of this breath which causes sneezing."
apparantly, i am a "Compulsive Photic Sneezer"