Vision is a complex process involving three phases: physical (acuity), physiological (integrative), and psychological (perceptual). Although these phases cannot be considered discrete, they provide the basis for the visual screening procedure used by the Reading Services of Colorado State University and described in this document. Ten tests are…

Studied infant ability to extract depth information from a three-dimensional structure. Found evidence that 8-month-old infants distinguished between lines indicating edges, and lines indicating markings, and that they are able to use line junctions to perceive line drawings as depicting three-dimensional objects in the picture plane. (Author)

The question of whether pupil diameter indicates information processing load during reading was investigated in three experiments involving 24 college students reading passages of varying difficulty. A TV camera and monitor, together with a video-recorder, were used to measure the diameter of the pupil under a reading condition and under three…