The optical nature of the reflector sight meant it was possible to feed other information into field of view, such as modifications of the aiming point due to deflection determined by input from a gyroscope . 1939 saw the development by the British of the first of these gyro gunsights, reflector sights adjusted by gyroscope for the aircraft's speed and rate of turn, enabling the display of a lead-adjusted sighting reticle that lagged the actual " boresight " of the weapon ( s ), allowing the boresight to lead the target in a turn by the proper amount for an effective strike
