A subretinal implant is advantageous over an epiretinal implant in part because of its simpler design. The light acquisition, processing, and stimulation are all carried out by microphotodiodes mounted onto a single chip, as opposed to the external camera, processing chip, and implanted electrode array associated with an epiretinal implant. The subretinal placement is also more straightforward, as it places the stimulating array directly adjacent to the damaged photoreceptors. By relying on the function of the remaining retinal layers, subretinal implants allow for normal inner retinal processing, including amplification, thus resulting in an overall lower threshold for a visual response. Additionally, subretinal implants enable subjects to use normal eye movements to shift their gaze. The retinotopic stimulation from subretinal implants is inherently more accurate, as the pattern of incident light on the microphotodiodes is a direct reflection of the desired image. Subretinal implants require minimal fixation, as the subretinal space is mechanically constrained and the retinal pigment epithelium creates negative pressure within the subretinal space.