Vehicle headlight and vehicle headlight system

A vehicle headlight mounted on a host vehicle, comprising:

• a light emitting unit that emits light of a changeable light distribution pattern toward another vehicle located in front of the host vehicle;
• a determination unit that determines information from a detection device that detects the other vehicle and generates a signal indicating a turn sign of the other vehicle;
• and
• a control unit that receives a signal indicating the other vehicle detected by the detection device and a signal indicating a turn sign of the other vehicle,
• wherein
• the control unit controls the light emitting unit such that, when the signal indicating the other vehicle is input, a region including at least a first region overlapping with an entire visual recognition portion for allowing a driver of the other vehicle to visually recognize the outside of the host vehicle in the light distribution pattern becomes a light reduction region in which a total light flux amount of light from the light emitting unit decreases as compared with that before the signal indicating the other vehicle is input, and controls the light emitting unit such that, when the signal indicating a turn sign of the other vehicle is further input in addition to the signal indicating the other vehicle, at least the first region in the light reduction region expands to a turning direction side indicated by the turn sign as compared with that after the signal indicating the other vehicle is input and before the signal indicating the turn sign of the other vehicle is input;
• the light reduction region includes a second region connected to a lower edge of the first region;
• a left edge of the second region is located on a right side of a left edge of the first region, and a right edge of the second region is located on a left side of a right edge of the first region;
• and
• a lower edge of the second region overlaps the other vehicle.