A head mounted display device includes a display, a light waveguide element, and a light shutter. The display periodically provides a display image. The light waveguide element receives the display image, generates a projection image according to the display image, projects the projection image from a second surface, and projects the projection image to a target zone from a first surface. The light shutter is adjacent to the second surface of the light waveguide element and is coupled to the light waveguide element. The light shutter is periodically disabled and enabled in an alternating manner.