Why would my blackmoores eye looks swollen and have red in it?

My Black Moore's eye is swollen it wasn't yesterday that i know of but it was red. Its been like that for like 3 days but just got swollen today. It has what looks like blood in it. I do have other fish in there with him such as sharks which haven't seemed violent,goldfish,little neon ones, parrot fish, angel fish, cleany fish that clean the bottom and some others i also have decorations like fake plants and rocks and little pebbles like in any fish tank covering the bottom. I really dont know whats wrong with him and i dont want him to die so please help. His eye was only swollen today that i know of and red for like 2 or 3 days. Please help!!!!!!!!!!!!!!!!!