An external device (20) includes a mount (22), which is placed in front of a subjects eye. A laser (24) is coupled to the mount (22) and emits radiation (26) that is outside of 380-750 nm. A partially-transparent mirror (23) is coupled to the mount (22). An intraocular device (30) is implanted entirely in the subjects eye, and includes a plurality of stimulating electrodes (38), and an energy receiver (32), which receives the radiation (26) from the laser (24) and generates a voltage drop. A plurality of photosensors (34) detect photons (33) and generate a signal. Driving circuitry (36) is coupled to the energy receiver (32) and to the photosensors (34), and receives the signals from the photosensors (34) and utilizes the voltage drop to drive the electrodes (38) to apply currents to the retina in response to the signals from the photosensors (34). Other embodiments are also described.