Approximately 20M people worldwise suffer from blindness that cannot benefit from recent genetic and neuroprosthesis developments in the retina. Stimulation of the brain visual pathways has been a promising strategy by inducing artificial percepts of light in blind patients through microstimulation using penetrating microelectrodes. Yet, the clinical translation of such a strategy is still challenging due to biological reactions to the implanted device. In this project we aim to build an optogenetic visual prosthesis that interfaces with the lateral geniculate nucleus (LGN).First in mice, a blue opsin is expressed in LGN neurons from transfection of an adeno-associated virus. Transfected animals are excited using visual stimuli and optically through microLEDs implanted into the LGN. Electrophysiological responses are recorded in the visual cortex using surface electrode arrays. The optogenetic response is visible in the cortex from local field potentials with spatially confined responses depending on the stimulation location in the LGN.In macaques, LGN injections of novel viral constructs by a robotic surgery tool is performed to screen for efficient neuron transfection. Optogenetic stimulation is evaluated in a terminal experiment under anesthesia. An intracortical electrode mounted with a small glass fiber is inserted into the LGN. The electrophysiological response to optogenetic stimulation is recorded in the LGN and using a large flexible electrode array placed subdurally on the visual cortex validating the first step of this optogenetic LGN neuroprostesis.These results will guide developments of subthalamic visual prostheses and to better understand the cortical visual system that can benefit blind patients.