🚀 go-pugleaf

>The only times I've noticed the sneezing reaction is when I am looking up into
>a bright sky, usually towards the sun.  It is pretty clear to me that there is
>a genetic basis to this reaction, and that its purpose is to keep you from
>looking at light so bright that it could damage your retina.  The bit about the
>sneezing occurring upon sudden exposure to bright light would be related to the
>fact that your pupil has not yet adjusted to the intensity change.

What better way to keep you from looking than to sneeze, since it is
impossible to sneeze with your eyes open.  :^)

Actually, I seems to me, that the sneeze is probably caused by some of
the chemical tranmitter from a nerve carrying an especially strong
signal leaking over to the nerves running to the nasal cavity.  I
wouldn't expect it to take much since it doesn't seem to take much of a
signal to cause a sneeze under normal conditions.  Don't lots of the
nerves from the face come close to the nerves of the nose where they
all enter the skull at a common point?  This would explain why some
people go into sneezing fits when they experience a sharp pain on the
face, such as a bee or jellyfish sting.  A friend of mine would hiccup
whenever he touched a certain spot on his jaw.