STEREOSCOPIC AND RESOLUTION ACUITY WITH VARYING FIELD OF VIEW

Resolution and stereoscopic acuity were measured while the field of view was varied in size--without, however, obstructing the targets for either eye. Resolution acuity showed no marked or regular changes, but stereoacuity was progressively reduced as the field of view was constricted. This supports the hypothesis that the sharp decline in stereoacuity is due to loss of peripheral visual stimuli and suggests that the introduction of such cues underwater should improve stereoacuity. Several possible explanations of the phenomenon are discussed.