I saw this over on The Fettig Project group at FB and thought it would be worth re-sharing here. Someone has created the 3d models for an eye mech and uploaded it to Thingivers: http://www.thingiverse.com/thing:1152248 So if you have access to a 3d printer you can print off the parts. They have a video showing the mech in action and how to assemble it. Here is one of the assembly videos.
I also wanted to share this preview video of a course available at Stan Winston School.
The full course can be purchased at the Stan Winston site here: https://www.stanwinstonschool.com/tutorials/how-to-make-an-eye-mechanism-design-3d-printing-assembly?utm_source=youtube&utm_medium=DCOV%20-%20%20How%20To%20Make%20An%20Eye%20Mechanism&utm_campaign=On-Demand%20Webcourse