A juvenile Indochinese Rat Snake (Ptyas korros) seen in a recent hike by Abdelhamid Bizid, who provides this photo and explanation.
"I posted this picture as the eyes of this snake look milky blue and wanted to give some explanation here. Snakes do not have eyelids but instead have specially adapted scales over their eyes, called eye caps, to protect their eyes. These eye caps are normally shed off along with the skin during the normal shed cycle but sometimes the caps do not come off properly and snakes get retained eye caps, like here. Usually, they will come off after a while, often at the next shed cycle. Retained eye caps can make the snake more aggressive (as they are impairing its vision) and sometimes even cause eye infections".