What to Look for When Sculpting the Eye
Do another eye study, this time at two times life-size. At this larger scale, it can be easier to see forms more clearly and understand where to add details. If you don't have a lot of clay, don't worry! You can establish and build out forms with newspaper or aluminum foil and masking tape before adding clay.
As you work, check your eye from the front and sides, as well as above and below as shown in this lesson to ensure you're maintaining accuracy.
You can sculpt from your own eye, or by using another reference.