ABSTRACT
It was more than a century ago when Emile Javal discovered that our eyes do not flow smoothly across a line of print but instead make a series of pauses called fixations and when psychologist Raymond Dodge invented a technique that could record those fixations. Soon after that, the implications of eye-movement data for reading research were seen as highly significant to understanding reading. The basic principle underlying Dodge’s technique—a harmless beam of infrared light directed at the reader’s cornea and reflected onto photographic film—is still in use today, although computers have replaced film, and the level of comfort, authenticity, accuracy, and general robustness of eye-tracking data have made substantial strides. The eye, like a camera, has a lens that must be at rest and in focus to provide a useful visual signal. So, as the eye moves across the text it stops and fixates at points in the text.
