Rise and shine: Morning blue light exposure, sleep, and work

In contrast to prior research demonstrating that blue light filtering glasses worn at night improve employee sleep and work outcomes, we build from circadian theory to examine whether morning blue light exposure may provide complementary benefits. A within-person field experiment prompted 182 full-time employees to wear blue light emitting glasses for 30 min each morning over two work weeks. Participants were randomly assigned to a treatment-first or control-first condition, with glasses programmed to emit either 100% (treatment) or 1% (control) blue light intensity. Results showed that morning blue light exposure improved sleep outcomes later that night, which enhanced next-day alertness, reduced depletion, and ultimately improved outcomes at work. Exploratory moderation analyses showed that employees with preexisting sleep problems and younger employees experienced greater benefits from blue light exposure in the morning, translating to meaningful improvements in work outcomes. This study provides evidence for a comprehensive 24-hr approach to light-dependent circadian regulation in workplace contexts. Additionally, it suggests that using blue light emitting glasses represents a simple, cost-effective intervention that organizations can implement to support employee performance, particularly for younger workers and those with existing sleep difficulties. (PsycInfo Database Record (c) 2026 APA, all rights reserved).