Would white pupils/irises on an animal allow it to see properly?
I'm designing creatures with naturally occurring white or pale grey irises and pupils so that it looks like their eyes are all white. What effect could this have their vision (colorblindness, light perception, etc)? Please note I'm not talking about leukocoria or eyeshine.
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The pupil is black not because it's coloured, but because there's no light coming back out to colour the image you see.
A pupil any other colour than black implies light coming back out, which in turn implies that the eye is not working at full efficiency. Light coming out means that not all the light that has gone in has been processed, so there may be missing parts of the image the organism sees or the image may just be dim.
It is, however, possible. The human eye has many layers or retinal receptor cells (the rods and cones that let you see light and colour). If an eye has just one or two layers, not every available millimetre of surface will be covered, so not every bit of light will be absorbed. This would seem to imply that the image seen would be incomplete, but since most of it would be there, the brain can fabricate the rest.
You would probably find that this animal moves its head a lot more to make up for not having complete vision. This ensures it sees all that's going on, including its potential prey.
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