squinting and brightness

[jb_farley]

hello everybody,

how come when it's bright out, and both my eyes are open, i squint a lot, but when i close one eye, the open eye doesn't have to squint as much?

like, there's an actual threshold of pain, and if i try and have both eyes open wide- it hurts like hell! but when i close one eye, the non-closed one can open much more.

it's weird, yo.

jb

[Mangetout]

I've noticed this before (I think I might have even started a GQ thread on it too) - I would venture to suggest that it is because vision, or rather perception, takes place in the brain - your eyes don't hurt because the light is too bright, but rather because your brain has decided that the light is too bright; why this decision is apparently based on the sum of the input from both eyes is a very interesting question.

I wonder if people (who for their entire lives have been) blind in one eye are able to tolerate less brightness than a person with one eye closed.

[Nametag]

Perhaps when you close one eye, the other one closes a little, too.