Evening home lighting adversely impacts the circadian system and sleep

This study examined how evening home lighting affects the circadian system and sleep using wearable spectrophotometers to measure light exposure. It found that energy-efficient lighting, such as LED and fluorescent lights, emitted higher melanopic illuminance (blue light levels) compared to incandescent lights. About half of homes had lighting bright enough to suppress melatonin by 50%, delaying sleep onset and increasing wakefulness. These findings highlight the impact of artificial light on circadian disruption, poor sleep quality, and related health outcomes like mood and cognitive impairments.

Limit exposure to bright and blue-enriched light from LEDs and fluorescents in the 3 hours before bedtime. Use dim, warm-toned lighting or incandescent alternatives to reduce melatonin suppression and improve sleep quality. This advice is strongly supported by evidence, though sensitivity to light varies individually. These changes can help preserve circadian health and enhance brain recovery during sleep.