ive seen this and heard about this a few times. all the times nobody really knew what to do. i think it is actually the skin around the eye that you usually dont see. but that is just a guess. if it is i would think that it could be cause by mite getting up there. try raising the humidity and giving it a soak or two. if that doesnt work after a week then you could wait till the next shed. if it doesnt go away by then you could ask a vet if you wanted to. this is what i would do, but i have no experience with it and really dont know what causes it. if you are really worried and cant find an answer...you could take it to a vet if you want to.