Objects look different sizes in the right and left eyes

Abstract

Coren and Porac (1976) reported that objects looked larger in the right eye of right‐eye dominant subjects and in the left eye of left‐eye dominant subjects. This paper attempts to repeat that finding. Two circles of same or different size were presented haploscopically in a binocular three‐field tachistoscope, to right or left visual half‐field and to the upper or lower visual field, one to the right eye and one to the left. A total of 43 subjects reported which of the two circles was the larger, each subject carrying out 120 trials of the experiment. Overall subjects reported that the stimulus to the left eye was significantly larger than that presented to the right eye. There was no association with eye dominance, and therefore the Coren and Porac finding could not be repeated. There was however a very significant association with handedness, left‐handed subjects tending to report that the stimulus in the right eye looked larger, and right‐handed subjects reporting that the stimulus in the left eye looked larger.