electrode looking down on their substrate plane and looking sideways to that view also showing the substrate 614 fig8 a depicts the location of an epiretinal electrode array 811 located inside the eye 812 in the vitreous humor 813 located above the retina 814 toward the lens capsule 815 and the aqueous humor 816 one aspect of the present embodiment shown in fig8 b is the internal retinal color prosthetic part which has electrodes 817 which may be flat conductors that are recessed in an electrical insulator 818 one flat conductor material is a biocompatible metallic foil 817 platinum foil is a particular type of biocompatible metal foil the electrical insulator 818 in one aspect of the embodiment is silicone the silicone 818 is shaped to the internal curvature of the retina 814 the vitreous humor 813 the conductive solution naturally present in the eye becomes the effective electrode since the insulator 818 confines the field lines in a column until the current reaches the retina 814 a further advantage of this design is that the retinal tissue 814 is only in contact with the insulator 818 such as silicone which may be more inactive and thus more biocompatible than the metal in the electrodes advantageously another aspect of an embodiment of this invention is that adverse products produced by the electrodes 817 are distant from the retinal tissue 814 when the electrodes are recessed fig8 c shows elongated epiretinal electrodes.