DEC 21, 2009
Researchers evaluated prehension proficiency in 20 adults with normal vision and 20 adults with long-term stereodeficiency as they reached for and grasped cylindrical objects while using both binocular and monocular vision. A second experiment examined the effects of temporarily mimicking similar stereoacuity losses in normal adults, by placing defocusing low- or high-plus lenses over one eye and a plano lens for normal binocular vision in the control eye.
Performance was faster and more accurate with normal binocular vision compared with reduced binocular vision and even worse with monocular vision. Movement duration was longer when stereo vision was permanently or temporarily reduced, and grasping error rates doubled.
The authors concluded that high-grade stereo vision is essential for skilled precision grasping. The results suggest that prioritizing the recovery of high-grade binocularity in amblyopic patients rather than only vision in the affected eye may improve visuomotor control, the authors said.