EYE-GAZE TRACKING DEVICE, EYE-GAZE TRACKING METHOD, ELECTRO-OCULOGRAPHY MEASURING DEVICE, WEARABLE CAMERA, HEAD-MOUNTED DISPLAY, ELECTRONIC EYEGLASSES, AND OPHTHALMOLOGICAL DIAGNOSIS DEVICE

An eye-gaze tracking device, which detects a gaze direction of a user based on an electro-oculogram, includes: a drift estimating unit which estimates drift noise included in a set of observation voltages among observation voltages that are electro-oculograms generated in a living body and observed at the plurality of electrodes, based on a component outside an electro-oculography subspace that is an assembly of sets of electro-oculograms theoretically observed at a plurality of electrodes; and an eye-gaze tracking unit which detects the gaze direction of the user, based on a signal generated by removing, from the observation voltages, the drift noise estimated by the drift estimating unit.