Easy way on how to draw manga eyes.
First draw the outside of were the eyelashes will go.
Now, draw were the pupil and color of the eye will go.
Now, pick the color of the eye and color it in. And in the middle use the brush tool, and draw a sort of half moon in the middle using a darker color.
Now draw some highlights in the darker part of the eye.
Draw the glare from were the light is coming from.
Clean it up and add eye lashes.
Draw were the skin folds over the eye. (As the red arrows indicate.)
And your done!! A manga eye just for you.