An eye movement tracking device that can be mounted to standard eyeglasses as disclosed. The device comprises an illumination source, a time-of-flight (TOF) camera and a processor. The source transmits energy within a frequency band from a location proximate to an eye of a person, such that at least a first portion of the transmitted energy is reflected off a lens of eyewear worn by the person to subsequently reflect off the eye, and such that at least a second portion of the transmitted energy is transmitted through the lens to reflect off objects in the person's environment. The TOF camera detects reflections of at least the first portion of the transmitted energy, and distinguishes them from other energy detected by the TOF camera in said frequency band, based on TOF principles. The processor uses the detected reflections of the first portion of the transmitted energy to determine eye position.