An eyeball detection device includes an imaging device that obtains a face image which includes the left and right eyeball images of the target person; a first distance calculating unit that calculates a first-type distance representing the distance between the target person and the imaging device; and an eyeball searching unit that performs a search for the left and right eyeball images from the face image and, when only one of the left and right eyeball images of the target person is detected, searches for the other eyeball image of the target person based on the search result regarding the already-detected eyeball image as obtained by the eyeball detecting unit, based on the first-type distance, and based on a second-type distance representing the distance between the left and right eyeballs of the target person.
EYEBALL DETECTION DEVICE, EYE-GAZE TRACKING DEVICE, EYEBALL DETECTION METHOD, AND MEDIUM