To raise the transmittance of transmitting light concerning a pupil detection method using a dye sensitizing element optical sensor, a pupil detection method using a pupil position detector and a transmission type eye-direction detector, the pupil position detector, and the transmission type eye-direction detector.

A metal oxide semiconductor film with large transition energy constituting the dye sensitizing element optical sensor is allowed to have a columnar structure which is vertically extended with respect to a transparent electrode formed on a substrate with the metal oxide semiconductor film formed thereon.