Start by drawing a big half circle, this will be the top of the eye. After you've done that, draw a line under it - this line should not be as round as the first. That's the main guidlines. Now draw a circle inside the eye.
Draw bold lines over and under the eye, these lines will be the eyelashes. After you've done that, draw a small line on the top of the eye. This is the eyelid. Then draw two small circles inside the circle you drew earlier.
Darken everything, draw an extra circle in the eye, draw a few eyelashes. And then you're done.