A review of the literature shows that in reading and picture viewing cognitive skills play a key role along with visual acuity. Optimal processing conditions are reached only with letter and object sizes that match both cognitive skills and visual acuity. Beginning readers with normal vision need larger letters than skilled readers. In reading, eye movements step the fovea, a high-acuity region 2 degrees diameter, at the physiological pace of the visual system about 4 times per second. A simple computer-based procedure is described that determines the best acuity- and skill-matched letter (or object) sizes in the context of an optimal reading eye movement speed of 8 deg/s.
