Reading and the Eye
Reading in the Brain by Stanislas Dehaene explains at length how we read. The first chapter starts with the eye. I was surprised that: “The fovea, which occupies 15 degrees of the visual field is the only part of the retina that is genuinely useful for reading.” Just 15 degrees of the visual field is useful for reading? No wonder then: “Our eyes do not move continuously across the page… They move in small steps.” In steps of 15 degrees coverage, that is. McConkie and Rayner’s experiment proves this window is real. The setup involves a special device that tracks eye movement of the wearer. It then changes the visual display on the screen accordingly. In real time . It shows only a few characters to the left and right of the center gaze, the rest it fills with x’s. We the pexxx xx xxx xxxxxxx xxxx xx xx xxxxxx xx When the eye moves, the screen gets updated to align where the gaze has moved: ...