Sunglasses with wide temples and thick frame severely constrict temporal visual field extent

Abstract

Purpose To compare the impact of two types of sunglasses on visual field and glare: one (“thick sunglasses”) with a thick plastic frame and wide temples, and one (“thin sunglasses”) with a thin metal frame and thin temples. Methods Using the Goldmann perimeter, visual field surfaces (cm2) were calculated as projections on a 30 cm virtual cupola. A V4 test object was used, from seen to unseen, in 15 healthy volunteers in the primary position of gaze (“base visual field”), then allowing eye motion (“eye motion visual field”) without glasses, then with “thin sunglasses”, followed by “thick sunglasses”. Visual field surface area differences superior to the 14% reproducibility error of the method and having a p‐value inferior to 5% were considered significant. A glare test was done using a surgical lighting system pointed at the eye(s) at different incidence angles. Results No significant “base visual field” nor “eye motion visual field” surface area variation were noted comparing tests done without glasses and with the “thin sunglasses”. In contrast, a 22% “eye motion visual field” surface area decrease (p‐value = 2.7.10‐13) was noted comparing tests done without glasses and with “thick sunglasses”. This decrease was most severe in the temporal quadrant (‐33%; p‐value = 6.3.10‐20). All subjects reported less lateral glare with the “thick sunglasses” than with the “thin sunglasses” (p‐value = 6.10‐5). Conclusion The better protection from lateral glare offered by “thick sunglasses” is offset by a severe temporal “eye motion visual field” surface area constriction.