An open/closed eye determination device equipped with an imaging unit (11) that photographs a region containing the eye of a test subject, an open-eye-width measurement unit (12) that detects the upper and lower eyelids of the aforementioned test subject the image photographed by the aforementioned imaging unit (11) and that measures the width of the open eye between the edges of said upper and lower eyelids, a filter unit (13) that filters the open-eye width measured by the aforementioned open-eye-width measurement unit (12), and an open/closed eye judgment unit (14) that judges the eye to be closed when the open-eye-width value-as measured by the aforementioned open-eye width measurement means being subtracted from the open-eye width obtained by the aforementioned filter unit (13)-is greater than a threshold value, and judges the eye to be open when the aforementioned difference is less than or equal to the threshold value. By means of this open/closed eye judgment device, it is possible to judge accurately whether the eye is open or closed without being influenced by the imaging conditions or the distance from the face.
OPEN/CLOSED-EYE JUDGMENT DEVICE, DEVICE FOR ESTIMATING DEGREE OF EYE OPENNESS, AND PROGRAM