A headlight device including a headlight configured to emit light frontward of a leaning vehicle to form a lower light beam, an upper central light beam, an upper left light beam and an upper right light beam, and a control device that controls light emission from the headlight without any user operation. The control device forms both the upper left and the upper right light beams while the leaning vehicle is traveling straight, and reduces a brightness of the upper left and upper right light beams, responsive to a vehicle being illuminated by the upper left and upper right light beams respectively, and forms the upper left and upper right light beams respectively while the leaning vehicle is turning left and right, and maintains the brightness of the formed upper left or upper right light beam regardless of whether any vehicle is illuminated by the upper left or upper right light beam.

An operation member is switchable between a first operation position, a second operation position, and a third operation position. When operating force is released while the operation member is at the third operation position, the operation member returns to the second operation position. The controller is switchable between a first mode and a second mode. In the first mode, the controller sets the headlight to high beam when the operation member is at the first operation position or the third operation position, and sets the headlight to low beam when the operation member is at the second operation position. In the second mode, the controller controls to change an illumination mode by the light according to a situation acquired by the situation acquisition unit. The switching from the first mode to the second mode is performed by holding the operation member at the third operation position for a first threshold time or more.

An operation member is switchable between a first operation position, a second operation position, and a third operation position. When operating force is released while the operation member is at the third operation position, the operation member returns to the second operation position. The controller is switchable between a first mode and a second mode. In the first mode, the controller sets the headlight to high beam when the operation member is at the first operation position or the third operation position, and sets the headlight to low beam when the operation member is at the second operation position. In the second mode, the controller controls to change an illumination mode by the light according to a situation acquired by the situation acquisition unit. The switching from the first mode to the second mode is performed by holding the operation member at the third operation position for a first threshold time or more.

A vehicle headlight includes a housing and a central area within the housing configured to emit high beam illumination from a high beam light source and configured to emit low beam illumination from a low beam light source. A pair of flow-through vents open to a front side of the housing and open to a rear side of the housing. A pair of outboard areas within the housing include supplementary light sources. The pair of outboard areas are positioned outboard of the pair of flow-through vents of the vehicle headlight.

A vehicle headlight includes a housing and a central area within the housing configured to emit high beam illumination from a high beam light source and configured to emit low beam illumination from a low beam light source. A pair of flow-through vents open to a front side of the housing and open to a rear side of the housing. A pair of outboard areas within the housing include supplementary light sources. The pair of outboard areas are positioned outboard of the pair of flow-through vents of the vehicle headlight.