< previous | next >              Close window Blind spot demonstration #1: Shut your right eye and look at the black dot on the right with your left eye. From about one and a half feet away, move your face slowly towards the screen. At a critical distance the circular hatched disk on the left will fall entirely on your blind spot and disappear completely. If you move your face closer still to the screen, the disk will reappear. You may need to "hunt" for the blind spot by moving your face to and fro several times until the disk disappears. Notice that when the disk disappears you don't see a dark void or hole in its place. The region is seen as being covered with the same light gray color as the background. This phenomenon is loosely referred to as "filling in." © | Updated October 2001