It sounds like your python is getting ready to or has shed.
Just before a snake sheds his skin a lubricating fluid gathers between the eye and the protective scale that covers it that fluid is what causes the blue color. it is nothing to worry about just keep the humidity in the cage up or place a wet towel over the heat source in the cage the lens will come off on its own as long as enough humidity is present. What ever you do, DO NOT TRY TO REMOVE THE SCALE YOURSELF. a snake can be injured if the lens is removed to soon and scar tissue will build over the eye causing several months of blindness for the snake. your Humidity should be at 85% for shedding