Where and when did the X's on eyes denoting death originate?

Question

In old cartoons you'll see that when a character was killed and/or died the animator put X's on the eyelids. Where and when did this come from?

Answer 1

Possibly some kind of ritual sewing of eye-lits? This ritual was known to some old religions and cults... Also, for manipulations with dead man's eyes, compare the old Greek customs.