The study of eye movements in reading allowed researchers to map out the perceptual span (moving window paradigm), the nature of the extrafoveal information extracted during a fixation, for instance orthographic and phonological information (boundary paradigm) or the relative influence of attention versus visual acuity drop-off in the perceptual span (parafoveal magnification paradigm).
By examining eye movements while reading, researchers were able to identify key aspects of perception, including the extent of visual processing (moving window paradigm), the types of information gathered from outside the direct line of sight (boundary paradigm), and the relative importance of focus versus decline in visual acuity within the perceptual span (parafoveal magnification paradigm).