PROBLEM TO BE SOLVED: To practically consider the deviation between the estimated gazing point and the actual gazing point as the difference between the left and right gaze directions becomes larger, when the gazing point is estimated in consideration of the left and right gaze directions evenly. To the extent that A first direction determining unit that determines a first direction that is the direction of the line of sight of the first eye of the subject, and a second direction that determines a second direction that is the direction of the line of sight of the second eye of the subject. Based on at least one of the determination unit and (i) the operation of the subject with respect to the device in which the gaze measurement device that measures the gaze of the subject is arranged, (ii) the state of the device, and (iii) the orientation of the face of the subject. , Comparing the assumed gaze direction, the first direction, and the second direction with an assumption unit that assumes the subject's gaze direction, and determines which of the first eye and the second eye is the dominant eye. A first determination unit. [Selection diagram] Fig. 14【課題】 左右の視線の方向を均等に考慮して注視点を推定した場合、左右の視線の方向の相違が大きくなるにつれて、推定された注視点及び実際の注視点のズレが、実用上問題となる程度に大きくなる。【解決手段】 被験者の第１の眼の視線の方向である第１方向を決定する第１方向決定部と、被験者の第２の眼の視線の方向である第２方向を決定する第２方向決定部と、（ｉ）被験者の視線を計測する視線計測装置の配された機器に対する被験者の操作、（ｉｉ）機器の状態、及び、（ｉｉｉ）被験者の顔の向きの少なくとも１つに基づいて、被験者の注視方向を仮定する仮定部と、仮定された注視方向、第１方向及び第２方向を比較して、第１の眼及び第２の眼の何れが利き目であるかを判定する第１判定部とを備える。【選択図】図１４
