How an earlier sleep time and morning blue light exposure affect body clock timing in young adults who stay up late

Adherence to a fixed advanced sleep/wake schedule resulted in an average circadian phase advance of 1.5±1.1 hours for dim light and 1.4±0.7 hours for blue light exposure.

• Both blue light and dim light exposure after waking led to significant shifts in circadian timing among participants.
• Participants with late sleep schedules showed improvements in their circadian alignment after following an advanced sleep schedule for 6 days.
• There was no significant difference in the magnitude of circadian phase shifts between the blue light and dim light groups.
• The findings suggest that fixed early sleep schedules alone may be effective in advancing circadian rhythms in young adults with subclinical delayed sleep phase disorder.

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