Moray Eels, at least the G. Tile is practically blind and I believe it cannot tell things apart. When I feed it, it goes after my feeding tongs which I rarely use, it goes after my hand, but it still cannot find krill or smelt until he bumps into it. When I walk up to the tank when he is hungry, he comes out, but he does that for everybody even though I am the only person that feeds him.
Some fish though, I believe can learn to recognize their owners. My rainbow wolf seems to recognize me and only really pays attention to me.