Abstract
Purpose :
To investigate how the mounting location of wearable devices affects the measurement of light intensity.
Methods :
Two commercially available wearable devices, HOBO and Clouclip, were used to compare the effects of different mount locations on light intensity measurement. We assessed the consistency of the measurements of the two devices by placing a HOBO and a Clouclip simultaneously in 26 different light environments and measuring the light intensity. To simulate the real-life usage scenarios of the two devices, we had 29 participants wear two HOBOs—one on the wrist and the other on the chest—along with a Clouclip on their spectacles for one day, meanwhile the light intensity was measured and analyzed.
Results :
When under the same light environments, the light intensity measured by the Clouclip was 1.09 times higher than that by the HOBO, with an additional 82.62 units (r2=1.00, P<0.001). When simulating the real-life scenarios, the mean light intensity at the eye-level position was significantly lower than that at the chest position (189.13±665.78 lux vs. 490.75±1684.29 lux, P<0.001) and the wrist position (189.13±665.78 lux vs. 483.87±1605.50 lux, P<0.001). However, there was no significant difference in light intensity between the wrist and chest positions (483.87±1605.50 lux vs. 490.75±1684.29 lux, P=1.00). Using a threshold of 1000 lux for outdoor exposure, the estimated light exposure at the eye-level position was significantly lower than that at the chest position (3.9% vs. 7.8%, χ2=266.14, P<0.001) and the wrist position (3.9% vs. 7.7%, χ2=254.25, P<0.001).
Conclusions :
Our findings revealed significant variations in light exposure among the wrist, chest, and eye position. Therefore, caution must be exercised when comparing results obtained from different wearable devices.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.