All eyes have the same basic sphere shape, but the upper and lower eyelids vary from face to face and determine the appearance of the eyes. The face is roughly five eye widths wide, and there is one eye width between the eyes. Start simply and then branch out with different looks as you study photos and faces.
blending stump
drawing/sketching paper
pencil
Start by drawing a circle.
Add an iris and a pupil to the middle of the circle. Draw upper and lower eyelids. These may partially cover the iris.
Extend the curve of the upper part of the original circle to form the crease in the upper eyelid. Do the same with the lower part of the circle to form the lower eyelid.
Outline the light reflections on the eye and darken the pupil with a pencil. Use a blending stump to move some graphite around the iris, to help shape the eyeball and the eyelids.
Add some pencil marks to the iris and some eyelashes if desired. Draw in the eyebrow.