Variation in Evening Light Exposure Pattern Between Myopes and Non-Myopes

Abstract Purpose Considering a broad range of ambient lighting conditions may impact myopia development and dim light exposure as a potential risk factor for myopia progression, this study investigates i) light exposure pattern of Indian schoolchildren in evening hours, and ii) difference in evening light exposure patterns between myopic and non-myopic schoolchildren. Method 136 Indian schoolchildren aged 9-15 years, with 46 myopes and 90 non-myopes were recruited. This study analyzed evening light exposure (6-10:00 pm) recorded using MyLyt wearable light trackers in 136 Indian schoolchildren (age range: 9-15 years). Statistical analyses were conducted to evaluate differences in average light exposure levels, maximum light exposure levels, and time spent at each various light exposure (≤30 lux, >30 lux, ≤100 lux, and >100 lux across all the tested days) in myopic (n=46) and non-myopic (n=90) groups. Results The median evening light exposure level across all participants was 27 lux, with participants spending only 2 [0-6] minutes (median [IQR]) in light levels >100 lux. Myopic children had significantly lower median light exposure levels than non-myopic children (24 [19-30] vs. 28 [21-42] lux, p=0.017), and significantly lower maximum evening light levels than non-myopes (162 [101-273] lux vs. 189 [129-396] lux, p=0.044). Additionally, myopes spent significantly less time in light levels >30 lux than non-myopes (18 [11-31] minutes vs. 30 [15-53] minutes, p=0.009). Conclusions Indian schoolchildren spend evening hours in dim light