A method is described of inserting guide wires into a lumen, for example into the human gastrointestinal tract. The thickness and doping concentration of the carrier injection layer are selected to reduce minority carrier injection by the carrier injection layer in response to an increase in operating temperature of the thyristor. A specifying unit specifies a first image, which corresponds to a first index value of the plurality of calculated index values, and a second image, which corresponds to a second index value, among the plurality of generated images. The electrically activatable material of the lens is configured to get to the light inhibiting state such that the lens prevents the transmission of visible light from entering into and reflecting out from the one or more vehicle lights to reduce the observability of the one or more vehicle lights.