Scientists are one step closer to creating a bionic eyeball, thanks to the McAlpine research group at the University of Minnesota. There, researchers 3D-printed layers of material that can translate light into patterns—essentially the basic function of our eyes. McAlpine’s work marks the first successful instance of 3D-printing semi-conductive material on a round surface. The “eyeball” is made up of three main functions: silver particles that act as a conductive connector, semi-conductive material that turns light into electricity, and cathodes that direct electric current. Together, they are 25% efficient at translating light into electricity, which is why the eyeball can detect basic shapes. The McAlpine group has previously printed bionic prototypes of organs, spinal cords, and ears, but this is their first successful eyeball.