Musannaf Ibn Abi Shaybah 28609 — The eyelids

Makhul said: When both eyelids were severed from the eye, people used to assign the full blood money (diyah), and they did so because the eye has no protection left after them. If one of them was severed, they assigned one-third for the lower and two-thirds for the upper, because the upper one serves the eye better than the lower: it covers the eye and keeps (external things) away from it.