carrier upper surface a ground plane 30 provides a ground electrode 31 which is operatively associated with each of the stimulating electrodes the ground electrodes have upper 32 and lower 33 portions with the lower portions connected to the electrode carrier upper surface 22 and with the ground electrode upper portions projecting outward from the electrode carrier upper surface in the illustrated embodiment there is one ground electrode paired with each stimulating electrode 24 but there could be more than one ground electrode paired with each stimulating electrode or a single ground electrode paired with multiple stimulating electrodes so long as at least one ground electrode is operatively associated with each stimulating electrode an insulator 35 is connected to the electrode carrier 21 the stimulating electrodes 24 and the ground electrodes 31 the insulator has an upper 36 and lower 37 surface with the lower surface connected to the upper portions 25 of the stimulating electrodes the upper portions 32 of the ground electrodes and the upper surface 22 of the electrode carrier as explained in greater detail in connection with procedures for fabricating the retinal microstimulator a window 40 which exposes the conductors which form the stimulating electrode and the ground electrode is etched in the insulator in the embodiment illustrated in fig1 through fig3 the upper surface 36 of the insulator forms a basement membrane contact surface however in alternative embodiments of the invention because the basement membrane is soft and can become conformal the tops of the electrodes can form the basement membrane contact surface in addition grooves and valleys may optionally be etched or formed in the basement membrane contact surface so long as they.