A pupil detection method includes a step of acquiring images by taking a facial image of a subject using each of a left camera and a right camera, a step of extracting one or more image candidate points serving as candidates for pupils from the images, a step of extracting points corresponding to a combination of image candidate points corresponding to the same point in a three-dimensional space as space candidate points, a step of selecting a pair of two space candidate points from the extracted space candidate points and calculating a distance between the selected pair, a step of excluding a pair of space candidate points where the calculated distance is not within a specified range, and a step of determining one or more pairs of space candidate points from the pairs not excluded and determining that a pair of pupils of the subject exist at the positions.
