Reading with Screen Magnification: Eye Movement Analysis Using Compensated Gaze Tracks

Eye movements while reading with screen magnification (which requires manual scrolling to center the magnified portion of the screen within the viewport) pose interpretation challenges. Standard representations in terms of alternating fixations and saccades don't apply to this case. This is because, during scrolling, eyes often track a moving text element, generating a movement akin to smooth pursuit. We propose a new representation that uses information from the mouse (which the reader uses to move the center of magnification) to undo the effect of magnification and scrolling. After this "compensation" operation, gaze tracks can again be described as alternating fixations and saccades. We present an analysis of gaze tracks obtained by applying this transformation on an existing dataset, recorded from low vision readers using two modalities of screen magnification. This analysis highlights similarities and differences in terms of dynamic properties of compensated gaze tracks vis-à-vis gaze during regular reading.