In my chibi art I usually just leave the pupils out, but with my realism I try to do eyes. I guess I mix anime and realism... because I like details... but whatever... Here's a character I've been working on and these are two different versions of her, I've tweaked both of them and am in the process of sketching out another one of her. Sorry for the size!
Original with all the other sketches on the paper erased:

Second with revisions (thinking of coloring hence the hair highlight lines):

Third (in progress, appologizing for the lightness of the bg it's the girl that I want advice on):