Retained eye caps are caused by improper humidity levels during the shedding period. BP's are especially prone to this becuase they require a pretty high humidity (60-65%) to shed successfully. The best thing I have found for BP's and shedding is a humid hide. Take a plastic container that will give the snake a nice tight secure spot to hide, cut a whole big enough for the snake to go through. Then put a layer of sphagum moss in the bottom of the hide and keep it moist from the time the snakes eyes go cloudy until the snake sheds.