Effects of Central and Peripheral Vision Occlusion on Motor Performance during Hand Coordination Tasks

Abstract

OCCUPATIONAL APPLICATIONS Our study examined the influences of visual occlusion on healthy adults during the performance of hand coordination tasks. We found that central vision occlusion, similar to that seen in age-related macular degeneration, reduced all aspects of prehension (grasp, reach, place, and return). In contrast, peripheral vision occlusion, similar to that seen in glaucoma, only affected grasp. Furthermore, the effects of vision occlusion were more pronounced during more complex prehension tasks. Age-related macular degeneration and glaucoma, which both cause vision occlusion, are common in older workers, and our results suggest that these disorders may adversely affect task efficiency and safety during complex hand coordination tasks. Further study of the effects of age-related vision issues are needed, though, to understand any effects on work disability among individuals with age-related visual disorders.TECHNICAL ABSTRACT Background: Vision loss is associated with changes in work performance that may result in work disability. Purpose: The current study was conducted to examine the effect of simulated central and peripheral vision loss on motor performance during hand coordination tasks in a sample of healthy adults. We hypothesized that central vision occlusion would have a greater effect on (1) hand coordination (increased time) and (2) upper body movement (increased path length) than either peripheral vision occlusion or normal vision (unoccluded). Methods: Nine healthy young adults with normal ocular histories completed two coordination tasks of varying visual complexity (insertion of cylindrical pegs and key-shaped pegs) under three visual conditions: central and peripheral vision occluded with special contact lenses and unoccluded vision. Outcome variables of time and path length (motion capture kinematic analyses) were calculated for four components of prehension (grasp, reach, place, return). Results: Central vision occlusion resulted in statistically significant but small reductions in grasp, reach, and place times compared to peripheral vision occlusion (p < 0.001, d = −0.24 to −0.58), and significant but small increases in path lengths for grasp, reach, place, and return (p < 0.05, d = −0.21 to −0.56). Differences in outcomes among the coordination tasks were dependent on task complexity.Conclusions: Simulated visual field loss resulted in slower hand coordination and increased upper body movement for central vision occlusion compared to peripheral vision occlusion. Using healthy adults allowed us to control for age-related impairments that could confound our ability to detect the effects of vision. With the increasing number of older adults with visual impairment who will remain in the workforce, we must further study the effects of vision loss on work performance in people with age-related visual diseases to determine what interventions may be necessary to mitigate their effects.