About a week ago my clown fish started swimming very quickly from the bottom of the tank to the surface almost jumping out. Then for about two days he just sat in the corner and was breathing very heavy. He seems to be back to normal and swimming around but I think he is blind. I tried to feed him and he misses the food. I've put a net right in front of him and he don't swim from it. Is there anything I can do for it? what would cause this? hes about 5 years old