My school gave out goldfish yesterday, and one of mine has an odd eye. One of the eyes looks like a normal fish eye, with both the cornea and the pupil, but the other eye is the same size, but just a black pupil (bad photo, it's the white fish on the right that I am worried about). It's as if the black bled into the white area.
Is my fish sick? Blind in that eye? If it's sick, should I separate it from the other fish?