Device, method, and system of high-speed eye tracking. A system includes: a set of illumination sources, to selectively generate illumination pulses towards a human eye in accordance with a particular timing scheme per illumination source and in accordance with a particular wavelength per illumination source; a set of optical sensors, to sense changes to one or more properties of reflections of the illumination pulses from the human eye in response to modifications in operational properties of the illumination sources; and a processor to process the sensed changes, and to generate one or more processing results that are based on the sensed changes.