The first electrode 11 and the second electrode 12 are provided on the surfaces of the nose pads 8 A and 8 B constituting the eyeglasses-type frame 2, and based on the result of the detection of the electrostatic potential by the electrodes 11 and 12, the eyeglass type frame 2 is mounted or not And determines the wearing state.眼鏡型フレーム2を構成する鼻パッド8A、8Bの表面に第1の電極11と第2の電極12を設け、電極11、12による眼電位の検出結果に基づき眼鏡型フレーム2の装着状態又は非装着状態を判定する。