Measuring attention bias in observers of strabismus subjects

Abstract

Despite the known negative psychosocial impact and the importance of facial aesthetics for individuals with strabismus, the gaze pattern of the presumed attention bias has not been documented previously. Thirty images (15 digitally reconstructed color photographs to show strabismus and 15 photographs of volunteers without strabismus) were viewed in random order by 25 naïve participants (age range, 23-63years; 15 females). Visual scan paths of participants were recorded using an infrared corneal image eye movement recorder, and the individual parameters of saccades, fixations, and dwell time were assessed using DataViewer software. Viewers primarily tended to fixate on the eyes, the nose was the next most prominent point of focus (both P<0.001). Time to first fixation and the presence of strabismus in the images presented were significantly associated (P<0.001). When the eyes were viewed, there was more time spent looking at the strabismic eye (P<0.001), although the number of fixations toward the eyes did not differ significantly between normal and strabismic faces (P=0.2). Our results confirm that the presence of strabismus in the features of the human face draws longer attention from the average viewer to the eye region, and particularly to the strabismic eye.