@balloon, I don't think they're actually blue. I don't know why the coloring covered his eyes, but I'm pretty sure it's a flaw, especially considering what 1fish2fish said about him being a cull. He is in a critter keeper-like tank (it's a store brand so I don't know the exact size) but in comparison to my other tanks, I'm guessing it's three or four gallons.
@1fish2fish, I wondered about that too when I first saw him, but I don't think so. He doesn't bump into things, can sense food a mile off, and ALWAYS knew when you were carrying his cup by the edges, not supporting it from underneath, so I don't think he's blind.