An eye-fatigue examining device and an eye-fatigue examining method capable of examining eye fatigue of a subject's eye regardless of an age of a patient are provided. The eye-fatigue examining device includes: a light quantity difference adjusting unit that increases a light quantity difference between lights respectively incident on right and left subject's eyes; a gaze direction detecting unit that detects gaze directions of the respective subject's eyes while the light quantity difference adjusting unit increases the light quantity difference; and a light quantity difference deciding unit that decides a specific light quantity difference at which a change in the gaze directions due to the increase in the light quantity difference occurs, based on the detection result of the gaze direction detecting unit.