Temporary Blue Eyes
Have you ever seen a snake with blue eyes?
As the creature gets ready to shed, its skin loosens over the eye (and the rest of the body). The shedding process makes the snake nearly blind and slows it down. This lasts 1 to 2 weeks and the snake can be (understandably) aggressive during this time. The skin is usually duller than usual but underneath is fresh sensitive skin readying for its debut.
Most snakes shed 4-8 times per year. Just like teenagers outgrowing tennis shoes, younger snakes tend to go through the process more rapidly than older snakes. And those feeding well also shed more often.
When the skin comes off in one entire piece that indicates a healthy snake but scarring and malnutrition can cause the snake to shed in several pieces.