help

I think that's just how he's drawn . . .

I think it's the cheek-to-eye dent, just inked like the rest of the rim. Meaning, no, not eyeliner.

I once heard that Egyptian eye makeup was made from coal & crushed ant eggs.

it's the way a lot of 日本动漫 characters are drawn. take Code geass from an example. they all look like they are wearing eyeliner. it's just the drawing style.