This rig is a part of a bigger character project.
Japanese 3D Designer Yoshimitsu Maruo, who is known for creating photorealistic digital portraits, has unveiled a stunning new project. This time, the artist has managed to set up a realistic eye rig that allows the character to look around and even blink. The rig, according to the author's Twitter page, is a part of a bigger character project currently in development. Unfortunately, not much is known about the working process behind the rig, however, the artist stated that Maya, Substance 3D Painter, and Arnold are being used for the character herself.
And here are some other WiP shots shared by Maruo: