LogFAQs > #911947545

_AdjI_ posted...

Mead posted...

do eyes absorb light

That's how they work. Photons get absorbed by proteins in the cells of the retina, causing their shape to change and triggering an action potential that the brain subsequently interprets.

Yeah, that's why your pupils get smaller or bigger in the presence of light. When it is bright outside, your pupils get smaller to prevent too much light getting into your eyes. When it is dark, your pupils get bigger to allow as much light as possible in.

That's why when you suddenly go from a very dark room to a very bright room, it can hurt your eyes temporarily because your pupils are big from being in the dark and then you go into a bright room and too much light is getting in your eyes. It takes a moment for your pupils to adjust and shrink.

Doctors also test your eyes by shining a light into your eyes. They are testing to see whether or not your pupils are properly changing size in the presence of light.