This was the reason that I first bought a 3d printer. I struggled with various ways to make animatronic eyelids for my ostrich character but they were never great. The 3d printer changed that. I think this was day 3 of owning my printer. Having specific goals made it much easier for me to learn to model in fusion360. Since then the entire ostrich head has become 3d modelled and printed, beak and all.
You can read about making the eyeballs themselves here.

