0928 The Self-Reported Practice of Light Exposure Recommendations in the Morning, Daytime, Evening, and Nighttime

Abstract Introduction While it is well known that ocular light strongly entrains the central circadian clock, there has been a lack of evidence-based recommendations for daytime, evening, and nighttime light exposure for healthy adults. Recently, an expert consensus report with recommendations for light exposure has been published. Although the general population is likely not yet acquainted with these recommendations, we examined the self-reported practice of daily and nightly light exposure based on these published guidelines. Methods Online survey data were collected from 168 participants through convenience sampling (age range: 25-80, mean age: 58.9 + 12.6 years, 55% female). The practice of expert, consensus-based light recommendations was assessed with 4 items on an 8-point frequency scale ranging from “Never” to “Every day of the week”. The scale covered 1) indoor daytime light recommendations, 2) indoor evening light recommendations, 3) nighttime light recommendations for the sleep environment, and 4) an additional morning-specific question. Results Within the first hour after waking up, the majority of respondents (53%) reported never receiving exposure to at least 15 minutes of sunlight or simulated bright light, with only 16% reporting exposure every day of the week. Throughout the daytime, 54% of respondents reported receiving consistent natural indoor light or sunlight every day of the week, and 8% reported never receiving any. During the evening, 47% of respondents reported never dimming lights and avoiding bright light starting at least 3 hours before bedtime. However, 24% reported avoiding bright light sources before bedtime every day of the week. While sleeping, nearly 80% of respondents reported keeping their bedroom as dark as possible, no brighter than natural moonlight, every day of the week, with only 10% reporting never doing so. Conclusion Self-reported practice of recently published light recommendations was poor for both morning and evening light exposure. These findings suggest that sleep and circadian health campaigns should focus on the importance of bright light in the morning upon awakening, and of dimmed light in the late evening before bedtime. Support (if any) SleepScore Labs