Why Does My Snake Have Milky Eyes?

A couple of weeks before a snake sloughs, the new layer of skin underneath secretes a milky fluid containing an enzyme that softens the old layer, causing the new and old layers to separate (pre-slough), the old skin becomes dull in colour and the eyes turn opaque or milky.

Black Pine from the UK (not available as a pet in WA).

Have you ever noticed that your python never closes its eyes?  This is because it doesn’t have eyelids, but instead has scales over its eyes to protect them from dirt and dust.  A healthy snake will shed its whole skin in one piece including the scales over its eyes. 

Snakes have poor eyesight and when their eyes turn milky, they can become virtually blind. This makes them very nervous and they can strike at anything near it, including your hand. Quite a few snakes won’t feed at this time, simply because they don’t feel safe.  During this time it's best to avoid handling or feeding until after the snake has shed.