Hey Dennis, The structure of your eye is good, nice job. When you render the eye, you have to really think of it as a 3D object. It will help your rendering bring out the form. I did a quick and dirty eye drawing to show you what I mean. I hope this helps, keep drawing :)

The eye is looking good structure wise and you've got a great start shading. Similar to what Mikoto said, try to get the lines and shading to be a bit more even and less rushed feeling. You're at a good point in the drawing to start pushing some edges more such as a softer edge along the brow ridge and some harder edges where the top of the eye socket is casting a shadow right corner by the tear duct.

Hi Dennis. Cool drawing :) really like the shape of the eye. I think you can boost the contrast a lot more. also I would add the eyelashes :)

Nice work. I can feel the dimenisions of the eye. But the lines are messy. Try sharpening the the pencil, draw the darker thin areas with that sharpened pencil. For the eyebrows, use the side of the pencil to lay out the values, then use the sharp edge for drawing the hair.

This looks cool! It seems accurate and we'll shaded to me, the one thing is mention is that you have used lots of little dark lines for the fold of the eye lid which ruins the effect of a single fold of skin and makes it look a bit hairy! So just be bold with that one! Great drawing 👍