Figure 8.4: Demonstration of the blind spot Close your left eye and focus on the X with your right eye. Start with the page a little more than a foot from your eye and move it gradually closer, still focusing on the X. At about 10 inches, the bird will disappear. At that location, the image of the bird falls on the blind spot of the retina, shown in Figure 8.3. Yet you will probably still see the bars of the cage running across the area where the bird was located, and the background color may fill the space previously occupied by the bird. The bars and color are perceptually filled in by your visual system.