Impaired binocular vision with bangerter foil and its influence on fine motor skills: a clinical observational,...

To analyze the influence of simulated impaired binocular vision on visual performance and fine motor skills (FMS).

A total of 33 young and healthy participants were included. A Bangerter foil 0.8 was employed to induce impaired binocular vision. Visual performance was assessed randomized, under three binocular viewing conditions: binocular baseline, wearing a Bangerter foil on dominant eye, and wearing Bangerter foils on both eyes, by visual functions: visual acuity, contrast sensitivity, disability glare, and stereopsis. Five tests evaluated fine motor skills: Purdue, O´Connor, and Grooved Pegboard; water pouring and threading task. The Overall Visual Performance Score (OVPS) and Overall Fine Motor Skills Score (OFMSS) were calculated.

Binocular visual performance was significantly worse when deterioration was induced simultaneously on both eyes for all visual functions tested (p < 0.05). There were no significant differences in visual acuity and near contrast sensitivity between deteriorated conditions in only one eye and baseline. However, the two visual impairment conditions differed significantly, except for stereoacuity. For FMS, the deterioration factor was also significant (p < 0.05). In terms of OVPS and OFMSS, the greater the induced binocular dysfunction, the worse the visual performance and ability to perform fine motor tasks (rho = 0.334; p < 0.001).

These findings suggest that mild monocular or binocular induced impairments have an impact on the visual functions measured and also have a marked effect on the performance of manual tasks that require fine motor skills. These results may be comparable to those from patients with recent-onset edema or cataracts; nevertheless, a full reproduction of the optical and neural effects of genuine pathology by the simulations is not achieved.