Effect of Full-Face and Half-Face Helmet on Functional Vision and Visual Reaction Time

BACKGROUND: Motorcycle helmets are one of the most important protective gears in the automotive industry. However, some riders think they hinder their vision, which leads to helmet non-compliance. Hence, thorough research is required to evaluate the same. AIM AND OBJECTIVE: To assess the effect of full-face and half-face helmets on functional vision and visual reaction time (VRT). SETTING AND STUDY DESIGN: Comparative experimental crossover study. METHODS: The subjects aged between 18 and 35 years and who gave written consent to participate were included. Functional vision and VRT were assessed with and without the helmets. Helmets tested included a full-face helmet and a half-face helmet. RESULTS: A total of 52 subjects aged 20 ± 1.5 years, participated in the study. Of those, 16 were males and 36 were females. The mean stereopsis without any helmet was 44.42 ± 6.3 arcs of second that reduced to 60.57 ± 13.34 arcs of second with a full-face helmet and to 60.38 ± 14.27 arcs of second with a half-face helmet. Repeated-measure analysis of variance showed a significant reduction in stereopsis in both types of helmets (P < 0.05) as compared to without a helmet. However, contrast sensitivity, VRT, and visual field did not show any significant difference (p > 0.05) when compared to the baseline or within the helmet types. CONCLUSION: The visor significantly affects the stereopsis while viewing through it. The study did not find the exact cause of this reduction, and hence, further evaluation is recommended.