Basic Model in C4D, then the "hull" is done via "Dynamesh", details with some "cloth"-alphamaps as well as UV-unwrapping in ZBrush, Textures in Substance Painter and Photoshop, Rendering in Marmoset.
Eyeball Turntables
Eyeball 01
Eyeball 02
Eyeball 03
Eyeball 05
Eyeball 04