why do I sneeze when it's bright outside?

Answer 1

Photic sneeze reflex

Photic sneeze reflex (also referred to as sun sneezing, photogenic sneezing, or whimsically called ACHOO, a backronym for Autosomal dominant Compelling Helio-Ophthalmic Outburst) is a medical condition by which people exposed to bright light sneeze. The photic sneeze reflex can also cause one to sneeze many times consecutively. The condition occurs in 17% to 25% of humans with more common occurrence in Caucasians than other human races. The condition is passed along genetically as an autosomal dominant trait.

The first mention of the phenomenon is probably in the later work attributed to Aristotle (Problems, book XXXIII).

The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus. The fifth cranial nerve, called the trigeminal nerve, is apparently responsible for sneezes. Research suggests that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneeze reflex. Another theory suggests that tears leaking into the nose through the nasolacrimal duct are a cause of the photic sneeze reflex. The speed of the reflex seems to favour the first theory, as it happens much too quickly for tears to be generated and drain into the nose. In addition this sneeze reflex can be brought on by a sudden inhaling of cold air or a strong flavor such as a strong mint gum. This implies an overstimulation of any nerve close to the trigeminal nerve can cause the sneeze reflex.

Answer 2

Photic sneeze reflex

Photic sneeze reflex (also referred to as sun sneezing, photogenic sneezing, or whimsically called ACHOO, a backronym for Autosomal dominant Compelling Helio-Ophthalmic Outburst) is a medical condition by which people exposed to bright light sneeze. The photic sneeze reflex can also cause one to sneeze many times consecutively. The condition occurs in 17% to 25% of humans with more common occurrence in Caucasians than other human races. The condition is passed along genetically as an autosomal dominant trait.

The first mention of the phenomenon is probably in the later work attributed to Aristotle (Problems, book XXXIII).

The probable cause is a congenital malfunction in nerve signals in the trigeminal nerve nucleus. The fifth cranial nerve, called the trigeminal nerve, is apparently responsible for sneezes. Research suggests that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the optic nerve triggers the trigeminal nerve, and this causes the photic sneeze reflex. Another theory suggests that tears leaking into the nose through the nasolacrimal duct are a cause of the photic sneeze reflex. The speed of the reflex seems to favour the first theory, as it happens much too quickly for tears to be generated and drain into the nose. In addition this sneeze reflex can be brought on by a sudden inhaling of cold air or a strong flavor such as a strong mint gum. This implies an overstimulation of any nerve close to the trigeminal nerve can cause the sneeze reflex.

Source(s):

From Wikipedia, the free encyclopedia

Answer 3

When its bright outside you tend to sneeze because we automatically look up to see the brightness, for some reason it triggers a sense to our nose that makes us sneeze.

Answer 4

I can't give you a scientific answer, but this was once told to me.

When the sun is out, it heats the earth and excites the pollen and dust particles in the air. Most people unknowingly inhale deeply the first time they are outside on a bright day.

Hence, they get a nose full of dust and pollen, and you guessed it, it overloads the nose and we sneeze.

Answer 5

Photic sneeze reflex

Answer 6

It is a parasympathetic reflex that about 10% of the population shares with you. It is triggered the constriction of your pupils in the bright light.

Aloha

Answer 7

You ever pinch the skin between your nose an lip and have to sneeze?

Answer 8

it may be that when it is bright, you squint. this causes your nose to wrinkle. your sneezing reflex may be really sensitive so doing this causes your sneeze reflex.

This is just a guess though.

Answer 9

Allergies?

Answer 10

The allergen theories are interesting; however, this also happens to me, but I have never had any sign of any type of allergy.