A method for controlling a vision prosthesis having an optical system in optical communication with the retina, the method including detecting a polarization state of light reflected from a retina; and at least in part on the basis of the polarization state, generating a control signal for causing a change to an optical property of the optical system. , to a call destination, such as a Public Safety Answering Point, over an Internet Protocol communication link. via the supply pipe; and storing the raw material in the mold or the crucible covered with the cap. When appropriate magnification processing is performed for print image data, any mechanical error of the conveyor mechanism is absorbed.