The instant application describes display device for switching display mode between first display mode for displaying stereoscopic images with eyewear device which adjusts incident light amounts to the left and right eyes, and second display mode different from the first display mode. The display device includes signal generator which generates timing signals for notifying timings of increasing the incident light amount to the left and right eyes in the first and second display modes or stop signals for stopping the adjustment operation, as control signals for the adjustment operation; and transmitter which transmits the control signals to the eyewear device. During the first display mode, the transmitter transmits the timing signals for the first display mode. Switching operation from the first to second display mode causes the transmitter to transmit the stop signal and then the timing signal for the second display mode to the eyewear device.