When you look at the eyes of really old portraits from lets say 1500 to 1800, its very rare to find eyelashes on the eyes, everyone has huge bulging eyes with no lashes, was it seen as a sign of beauty to not have them.
I suspect it was because eyelashes get sun and fade, there was no mascara in those days. I did a web search and couldn't find anything so this is just a guess.
