The experiment design. The design was 2 × 2 factorial with factors: (1) The side of rotation of the nonviewing eye, left (A, C) or right (B, D); (2) The visual hemifield of target presentation, left (A, B) or right (C, D). The dashed line indicates the perceived direction of gaze in the viewing eye, shifted approximately 2° in the direction of rotation of the nonviewing eye (see Results section). The hypothesis was that visual sensitivity will increase in the same direction (arrow).