About 2 years ago I bought an Iridescent Shark and I've had no problems except that lately I've noticed that both its eyes have a white spot in the middle, and one of its eyes is red. It almost looks like the color on the red eye has been for lack of a better term "erased"? All my water conditions are fine and the only other fish I have in the tank is another Iridescent Shark that I bought last year. The shark also seems to be behaving and eating normally. Is this just due to the hyperactive nature of the species or this is a disease that I should be concerned about?