I was just wondering if anybody could answer the age old question as to why sunlight, or even bright light, makes some people sneeze.
I once had a professor tell me it is because your eyes tear in bright light and as it drains it tickles your nose. That is complete bull for many reasons: 1. I don't sneeze when I cry. 2. I sneeze almost instantaneously when exposed to bright light, there is no time for tears to form and drain. My theory is all about CN V. It is responsible for sensory of the nasal cavities and much innervation of the eye, including the cornea, and of course much more. As we all know, if your nasal cavity is irritated (stimulation of CN V), you will probably sneeze. If a person has a corneal abrasion, they are often photophobic, therefore light can stimulate CN V through a number of mechanisms. So, my theory is basically or referred pain. The light irritates the eye some how and your brain interprets it as a nasal irritant. Therefore, in bright light you are trying to sneeze away the Sun! What do you all think? I have not found a better theory anywhere else.
