A snake sheds about once a month as it is growing its first year or two. As snakes bodies prepare to shed a milky substance develops between the old skin and the new one. This causes the snakes get opaque and dull and their eyes often turn blueish or gray as well because they are essentially blind at that time. After 4-7 days they clear up some then within a few days they will shed.
During this time that he is pre-shed it would help to have some extra humidity to aid in preparing the skin to shed in one peice as it should...like misting the cage each day or putting him in moist hide ( a tupperware container filled with a damp washcloth or damp moss or damp papertowels, etc ) .
When he does shed you want to check him afterwards and make sure all the extra skin came off , especially from his eyes and the tip of his tail.
I hope this information helps.
Regards