Quantitative Evaluation and Optimization of the Light Environment in Sleep-Conducive Workplaces

Sleep is an essential physiological process, and residential lighting environments significantly impact sleep quality. To address circadian phase delays exacerbated by pre-sleep smartphone use in youth, this study developed targeted lighting interventions. Through laboratory simulations, the effects of color temperature, illuminance, and horizontal blue light ratio on multisensory responses (visual, psychological, physiological) and sleep quality were examined. A rhythmic lighting strategy for healthy environments was proposed. Key findings: (1) Lighting factors revealed a hierarchy of influence on sleep quality—color temperature had the greatest influence on sleep quality, followed by illuminance and horizontal blue light ratio. Optimal conditions include cycling color temperature, 800 lx illuminance, and 25% blue light ratio. (2) Context-specific interventions were proposed—high illuminance with low color temperature enhances comfort in healthcare/leisure spaces, while medium–high color temperature, high illuminance, and cycling blue light ratios improve efficiency in office/study environments. (3) A time-sequenced rhythmic lighting scheme aligned with daily routines was implemented. This study establishes a novel health evaluation framework for residential lighting, combining sleep quality, psychological, and physiological metrics, redefines research paradigms for light-induced health effects, and provides actionable insights for optimizing workplace lighting.