Résumé : | SIGNIFICANCE: Using static depth information, normal observers monocularly perceived equidistance with high accuracy. With dynamic depth information and/or monocular viewing experience, they perceived with high precision.
Therefore, monocular patients, who were adapted to monocular viewing, should be able to perceive equidistance and perform related tasks.
PURPOSE: This study investigated whether normal observers could accurately and precisely perceive equidistance with one eye, in different viewing environments, with various optical information and monocular viewing experience.
METHODS: Sixteen normally sighted observers monocularly perceived the distance (5 to 30 m) between a target and the self and replicated it either in some hallways that contained ample static monocular depth information but had a limited field of view or on a lawn that contained less depth information but had a large field of view. Participants remained stationary or walked 5 m before performing the task, as a manipulation of the availability of dynamic depth information. Eight observers wore eye patches for 3 hours before the experiment and gained monocular viewing experience, whereas the others did not. Both accuracy and precision were measured.
RESULTS: As long as static monocular depth information was available, equidistance perception was effectively accurate, despite minute underestimation. Perception precision was improved by prior monocular walking and/or experience with monocularity. Accuracy and precision were not affected by the viewing environments.
CONCLUSIONS: Using static and dynamic monocular depth information and/or with monocular experience, normal observers judged equidistance with reliable accuracy and precision. This implied that patients with monocular
vision, who are better adapted than participants of this study, should a so be able to perceive equidistance and perform distance-dependent tasks in natural viewing environments. |