PURPOSE: To provide a dazzling preventing device in which illuminance dazzling eyes can be recognized by a clear reference. CONSTITUTION: A dazzling preventing device is provided with an optical filter member 3 in which transmissive light quantity can be electrically controlled, and an electric control unit 10 equipped with an optical sensor 8 connected with an optical filter member 3. The electric control unit 10 changes the transmissive light quantity of the optical filter member 3 according to the total amounts of a light irradiated to the optical sensor 8. This dazzling preventing device is controlled by the intensity of the light irradiated to the light receiving face of the sensor 8, and the intensity of the light is selectively measured by plural different photoelectric transforming members (receiving surface area parts). The maximum value is selected, and used for the adjustment of the increase or decrease of the transmissive light quantity in the filter member 3. In this method, the dazzling preventing device can be controlled with high efficiency as long as a point light source with dangerous intensity is clearly recognized except for an intensive but unclear light without any influence strong enough for denying the control of the filter member 3.
DAZZLEMENT PREVENTING DEVICE AND CONTROL METHOD THEREOF