Well I'm not the best at drawing eyes...but I'd say that you should make the dark parts extra dark and the light parts extra light. Basically the more contrast the better Other than that, just pay a lot of attention to detail...try to copy from a photo that is very good quality so you can zoom and see the details easier. Also try to draw one that is from an interesting angle...straight on eyes can tend to be boring Hope that helps!
woah yeah that helps! i usually get a picture, save it to my phone and look at it when i draw later on but i never find any good quality eye pictures. Link? sorry if i am pestering you, i usually dont ask people for help or tips but you seem to know what your talking about!
Haha no problem Hmm...the picture I found was on this website actually. The reference is here: [link] (the download quality is REALLY good ) I'm sure you can find some other really good ones here. I'll keep an eye out for ya