Okay so I woke up yesterday to look at my fish tank and one of my black skirt tetras looks like its eye is like popping out of its head. The whole left eye looks as though it out of the head. At first I was super worried but im not really sure what to feel. He still eats and swims fine. His behavior hasnt changed its just that darn eye. I think its called "pop eye". I did what I could to help. I rose the temperature a few degrees, I did a water change, and I check my parameters and they looked fine. Im not sure weither to be worried or not. Can someone please help me?