I went down a bit of a rabbit-hole there. Apparently, the current belief is that the meaning is "If the eye is healthy, it functions as the light of the body and indicates that the owner is sincere, generous and helpful." [0]
I find it oddly reductive, unsubstantiated, and meaningless.
I find it oddly reductive, unsubstantiated, and meaningless.
Perhaps I'm not the intended reader :P
[0] http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S...!