A display system including a display device and an image processing device is provided. The display device includes a second display panel overlapping with a first display panel on the display surface side. The second display panel has a region that transmits visible light adjacent to a display region. The region that transmits visible light of the second display panel overlaps with a display region of the first display panel, which makes a non-display region between display regions of two display panels in the display device small. The image processing device has a function of correcting the gray scale, which is included in image data, corresponding to at least one of a portion overlapping with the region that transmits visible light and a portion not overlapping with the region in the display region of the first display panel.