Did you know that snakes have a scale over their eyes? Snakes don't have eyelids and they never blink. The scale over the eye protects the sensitive ocular tissue from damage.
One of the first signs a snake is going to shed its skin is cloudy eyes. The scale over the eye begins to lift as a new one replaces it. It turns milky in color while the new layer is formed. It becomes clear right before the snake sheds.
Ashley the Anaconda, about to shed.