A pupil detection apparatus (100; 700; 900) comprising: a first imaging pair (111, 112) composed of an imaging section and a light-emitting section that emits light at a time of imaging separated by a predetermined separation distance; a second imaging pair (121, 122) for which the predetermined separation distance is greater than that of the first imaging pair; a detection section (103, 104) that detects a first pupil image from a first person image in which a person is imaged by means of the first imaging pair (111, 112), and detects a second pupil image from a second person image in which the person is imaged by means of the second imaging pair (121, 122); an accuracy value calculation section (151, 152) that calculates a value of red-eye occurrence intensity that is relative brightness of brightness within the first pupil image with respect to brightness of a peripheral image outside the first pupil image, and, based on the correlation characteristic curve of red-eye occurrence intensity and pupil detection accuracy value of the first imaging pair (111, 112) prepared beforehand, determines a pupil detection accuracy value corresponding to the calculated red-eye occurrence intensity value; and a selection section that selectively outputs the detection result of the first pupil image or the detection result of the second pupil image based on a time variation trend of the determined pupil detection accuracy value, wherein the selection section selects the detection result of the second pupil image when all the determined pupil detection accuracy values in a predetermined period are less than a predetermined threshold value, and the time variation trend of the determined pupil detection accuracy value is an unrelievedly decreasing variation trend characteristic, selects the detection result of the first pupil image when all the determined pupil detection accuracy values in a predetermined period are greater than the predetermined threshold value, and the time variation trend of the determined pupil detection accuracy value is an unrelievedly increasing variation trend characteristic, if neither of the two criteria is satisfied, selects whichever pupil detection result was selected the previous time. a first imaging pair (111, 112) composed of an imaging section and a light-emitting section that emits light at a time of imaging separated by a predetermined separation distance; a second imaging pair (121, 122) for which the predetermined separation distance is greater than that of the first imaging pair; a detection section (103, 104) that detects a first pupil image from a first person image in which a person is imaged by means of the first imaging pair (111, 112), and detects a second pupil image from a second person image in which the person is imaged by means of the second imaging pair (121, 122); an accuracy value calculation section (151, 152) that calculates a value of red-eye occurrence intensity that is relative brightness of brightness within the first pupil image with respect to brightness of a peripheral image outside the first pupil image, and, based on the correlation characteristic curve of red-eye occurrence intensity and pupil detection accuracy value of the first imaging pair (111, 112) prepared beforehand, determines a pupil detection accuracy value corresponding to the calculated red-eye occurrence intensity value; and a selection section that selectively outputs the detection result of the first pupil image or the detection result of the second pupil image based on a time variation trend of the determined pupil detection accuracy value, wherein the selection section selects the detection result of the second pupil image when all the determined pupil detection accuracy values in a predetermined period are less than a predetermined threshold value, and the time variation trend of the determined pupil detection accuracy value is an unrelievedly decreasing variation trend characteristic, selects the detection result of the first pupil image when all the determined pupil detection accuracy values in a predetermined period are greater than the predetermined threshold value, and the time variation trend of the determined pupil detection accuracy value is an unrelievedly increasing variation trend characteristic, if neither of the two criteria is satisfied, selects whichever pupil detection result was selected the previous time.