Personally I'd not suggest a wet pillow case it can become air tight (and water tight think canvas buckets) and fall upon the snakes nostrils and suffocate it. I local person had this happen this month.
The best thing is simply to leave it alone and do nothing it will come off next shed just fix the humidity issue.
It is hard to say from you description what is going on. Is it possible that the dark eye was always dark and the light side was always light? I have a couple that are not completely symmetrical.
The scale is called a spectacle or brille, if you have actually removed the spectacle scale there is little to be done. Make sure it is clean and looks ok if it looks odd it is time for a vet. If you are not currently using paper it might be a good idea until the it heals or the next shed. Lets hope that the spectacle is intact and it is just a case of nerves. Fingers crossed.