Spherical Puppet Eye Blank

I think this un-altered file prints a 2.5" (63 mm) diameter spherical eye shape with a flat bottom. Of course it should be scalable in any good slicing program. This eye is great for glue-into-foam applications, using an adhesive magnet on the back, or drilling a center hole on the flat and using heat-press threaded inserts to attach it with a machine screw. (You will want a large plastic washer behind it if attaching with a bolt)

I created both of the eye pairs pictured here with this file using matte white PLA,  and while they look ok as-is they'll look even better if you sand the surface well and use a good quality filling spray primer. Repeat that process a few times for a flawless surface. 

You can also use a dremel to carve out relief spaces for pupils/irises.