An eye tracking system includes a pair of glasses including two frames; a light scanning projector coupled to the pair of glasses and operable to scan a beam of light to project an image frame including a plurality of pixels; an eyepiece mounted in one of the two frames and optically coupled to the light scanning projector; one or more photodetectors coupled to one of the two frames and operable to detect time-varying reflected signals; and a processor coupled to the light scanning projector and the photodetectors. The eyepiece includes an exit pupil expander operable to direct a portion of the beam of light towards an eye of a user. Each of the time-varying reflected signals is associated with the plurality of pixels. The processor is operable to correlate the time-varying reflected signals with the plurality of pixels and determine a first eye orientation.