The disclosure relates to a method of determining a gaze distance, the method including obtaining a plurality of images by capturing each of both eyes of a user, determining, from each of the plurality of images, a corner point located at an edge of the eye, a location of a pupil, and an eye contour, determining each of gaze directions of both of the eyes based on a difference between a reference point and the location of the pupil, wherein the reference point is determined based on the eye contour and a location of the corner point, and determining a gaze distance based on a difference between the gaze directions of both of the eyes.