What would happen if you lost the whites in your eyes?

Answer 1

if im not mistaken, i dont think it would do anything except possibly, slightly blur your vision. id think it would be something like popping a blood vessel in your eye.

Possibly in the early evolutionary history of the eye it was necessary for the retina to be effectively shaded from all light except that which came through the pupal. As early eyes were external small and their components thin this was a valid concern. If you close your eyes and look towards the sun you can see that significant light can make it through something as thick as your eyelids. To effect this shading a white coat, the sclera (whites of the eye) enveloped the eyeball except for the pupal. As white reflects all light it is the best shader (black absorbs light and as a consequence heats-up and re-emits.)

In the higher animals such shading is no longer really necessary as the eyeballs are mostly embedded inside a skull which takes care of any necessary shading much better than the white colour of the sclera ever could. As a consequence some higher animals have lost the white colour in their eyes: horses and some lizards.

So if a person were to loss the white colour of his sclera it wouldn't effect his vision all that much, if at all. It would make him look a little peculiar though.