A retinal prosthesis including an electronic stimulation unit housed inside an eye and including: a plurality of electrodes that contact a portion of a retina of the eye； an electronic control circuit, which is electrically connected to the electrodes and supplies to the electrodes electrical stimulation signals designed to stimulate the portion of retina； and a local antenna connected to the electronic control circuit. The retinal prosthesis further includes an electromagnetic expansion housed inside the eye and formed by a first expansion antenna and a second expansion antenna electrically connected together, the first expansion antenna being magnetically or electromagnetically coupled to an external antenna, the second expansion antenna being magnetically or electromagnetically couple to the local antenna, the electromagnetic expansion moreover receiving an electromagnetic supply signal transmitted by the external antenna and generating a corresponding replica signal.
