system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it that the whites of human eyes are very visible, while they aren't visible in other mammals (i.e.- cats, dogs, deer)?
gpt
I read somewhere (might have been here) that the whites in our eyes were a social evolution that allow us to see where someone is looking. This is useful for conversation. In addition, as hunters this would allow us to share direction of sight without actually speaking or moving.