Five wearable sensors for objective measurement of near work and light exposure

This study compared five wearable sensors (VEET, Clouclip, Actiwatch, ActLumus, and GENEActiv) for quantification of myopia-related environmental exposures. Thirty participants (27.8 ± 7.0 years) simultaneously wore two spectacle-mounted and three wrist-worn sensors for one day while maintaining a detailed activity log. Data were binned by viewing distance (near: 15– < 60 cm, intermediate: 60– < 100 cm, far: ≥100 cm) and illumination (scotopic: <3 lux, mesopic: 3 to < 30 lux, indoor photopic: 30 to <1000 lux, outdoor photopic: ≥ 1000 lux). The VEET recorded significantly more near and intermediate time than the Clouclip ( p < 0.001). Activity logs yielded significantly lower near viewing compared to the VEET ( p < 0.001) and Clouclip ( p = 0.048) and higher intermediate viewing time ( p < 0.001). All sensors demonstrated excellent agreement for categorizing outdoor illumination. Activity logs reported significantly greater outdoor durations compared to the VEET, Clouclip, GENEActiv and Actiwatch ( p < 0.05 for all). The Actiwatch recorded significantly greater scotopic ( < 3 lux) durations compared to other sensors (p < 0.05 for all). While subjective logs provided useful contextual information, visual activity estimates were significantly different than objective measures. Small but significant discrepancies across sensors emphasize the importance of device selection in myopia research.