Well my adult angel fish has developed some kind of a 'defect' right on the actual eye. But it does not look like a grain of salt, it looks a lot like an air bubble but has been there a couple weeks now and she doesn't seem sick otherwise. There's no other similar spots on her nor on any of my other fish. Also I haven't added any new fish in over a year and a half. I tried taking a photo but it seems impossible to capture what it looks like in real life.