1. A method for stimulating neurons of a brainstem or midbrain of a patient to provide sensations for the patient, the method comprising: generating a plurality of light signals that, when applied to a neuron of a person, can stimulate a nerve action potential in the neuron; delivering the light signals to a plurality of neurons of the brainstem or midbrain of the patient; and selectively controlling the plurality of light signals to optically stimulate the plurality of neurons in order to control nerve action potentials (NAPs) produced by the plurality of neurons.