Fig. 5.

Hermetic retinal prosthesis and associated primary power and data coils. The implant on the left is a prototype of the device in Fig. 4, shown attached to a plastic model eye. The gold power secondary coil and center-tapped data secondary coil were formed as one piece on a sphere to match the eye’s curvature. The titanium case with welded lid, hermetic feedthrough, and epoxy header protected the internal circuitry. The electrode array is out of view over the top of the model eye. The primary coils on the right were potted in poly(dimethylsiloxane) (PDMS).