Apparatus, comprising: an external device, comprising: a mount, configured to be placed in front of an eye of a subject; and a power source coupled to the mount and configured to emit radiation that is outside of 380-750 nm; and an intraocular device configured to be implanted entirely in the subject's eye, the intraocular device comprising: an energy receiver, configured to receive the radiation from the power source and to generate a voltage drop in response thereto; a plurality of stimulating electrodes; a plurality of photosensors, each photosensor configured to detect photons and to generate a signal in response thereto; and driving circuitry, coupled to the energy receiver and to the photosensors, and configured to receive the signals from the photosensors and to utilize the voltage drop to drive the electrodes to apply currents to a retina of the eye in response to the signals from the photosensors, characterized in that the external device is configured to modulate the radiation emitted from the power source using an encoding protocol, and wherein the driving circuitry is configured to regulate a stimulation parameter of operation of the driving circuitry in response to the modulation of the radiation emitted from the power source. an external device, comprising: a mount, configured to be placed in front of an eye of a subject; and a power source coupled to the mount and configured to emit radiation that is outside of 380-750 nm; and a mount, configured to be placed in front of an eye of a subject; and a power source coupled to the mount and configured to emit radiation that is outside of 380-750 nm; and an intraocular device configured to be implanted entirely in the subject's eye, the intraocular device comprising: an energy receiver, configured to receive the radiation from the power source and to generate a voltage drop in response thereto; a plurality of stimulating electrodes; a plurality of photosensors, each photosensor configured to detect photons and to generate a signal in response thereto; and driving circuitry, coupled to the energy receiver and to the photosensors, and configured to receive the signals from the photosensors and to utilize the voltage drop to drive the electrodes to apply currents to a retina of the eye in response to the signals from the photosensors, characterized in that the external device is configured to modulate the radiation emitted from the power source using an encoding protocol, and wherein the driving circuitry is configured to regulate a stimulation parameter of operation of the driving circuitry in response to the modulation of the radiation emitted from the power source. an energy receiver, configured to receive the radiation from the power source and to generate a voltage drop in response thereto; a plurality of stimulating electrodes; a plurality of photosensors, each photosensor configured to detect photons and to generate a signal in response thereto; and driving circuitry, coupled to the energy receiver and to the photosensors, and configured to receive the signals from the photosensors and to utilize the voltage drop to drive the electrodes to apply currents to a retina of the eye in response to the signals from the photosensors, characterized in that the external device is configured to modulate the radiation emitted from the power source using an encoding protocol, and wherein the driving circuitry is configured to regulate a stimulation parameter of operation of the driving circuitry in response to the modulation of the radiation emitted from the power source.