And finally the last one, which is looking right.

This is how your blend shapes need to look like… so when you make eye shape to look like the one shown in the picture just press SHIFT + D and make copy of that shape and move to side… than next one.. copy.. move to side.. until you have all your blend shapes duplicated. When you have all of them put you move base eye in starting position by putting 0 to rotation values for both clusters. Then delete clusters on your eye so now you have just object like the one we started with this tutorial. No clusters, no extra nodes and deformers. Here is how scene looks now with all blend shapes on side and base mesh reseted to start position and clusters deleted.

Now lets put those shapes to blend shape node of eye! Select all shapes and than SHIFT + Select base mesh. When you got them selected in that order go to animation panel in maya and go to Create deformers / create blend shape. Now you would be having 4 blend shapes in objects stack. New deformer on eye shape that allows you to morph your base shape in every one of those 4 that you made and combinations between them. If you open blend shape window which is in window/animation editors/ blend shape you should see 4 sliders that allows you to morph your base shape and change its shape.

Now we are going to use those shapes to drive them to follow eye movement with driven keys. So let’s setup this scene fast. We gonna make some basic shapes like circle and square for that. Make one nurbs square 4x4 and one nurbs circle with radius of 2 and place them like as shown in the below picture, to place circle in the middle of square.