Crowding, a neurological phenomenon that impairs peripheral recognition of flanked characters, fundamentally limits the number of letters that can be perceived at a glance [10]. Therefore, in order to read efficiently, attention must be directed to the uncrowded span of text, centered at fixation [54], as the gaze shifts during reading. We suggest that attention deficits associated with dyslexia make this a challenge by disrupting processes needed to maintain attention to the uncrowded span, as fixations advance from one word to the next [1].
