A light combiner combines first light provided by a light source with second light containing an image of an exterior environment and provides the combined light to a user. The light combiner includes a transmissive optical device comprising a first surface on which the first light is incident and a second surface facing the first surface, and branching the first light in a plurality of directions to pass through the second surface, and a holographic optical device on a side of the transmissive optical device facing the second surface and spaced apart from the transmissive optical device. The holographic optical device diffracts light rays branched and transmitted by the transmissive optical device in the plurality of directions, to be respectively focused at a plurality of focal points different from each other and corresponding to the directions, and transmits the second light therethrough to travel toward the plurality of focal points.