Today, I was working on my tank and after I was done I sat and watched my fish. When I discovered that my Flame Angel has a kinda sheer white face. I can see it under certain light but not that much when the lights are in feeding mode. He is behaving normal, is very active, feeds, and there is no scratching. No other fish show any symptoms or white face. No fish were added recently. Does he have a disease? Sorry for the bad pictures, but as I said he is moving around a lot like he knows I am taking pictures of him.