Light Exposure

Light Exposure

Articles tagged with "Light Exposure".

Light Exposure Patterns Predict Sleep Timing and Daytime Sleepiness

Tags: Light Exposure, Sleep Timing, Daytime Sleepiness, Light Patterns

October 22, 2025

How Do Your Daily Light Exposure Patterns Affect Sleep Timing and Alertness?

Daily light exposure patterns strongly predict sleep timing and daytime sleepiness, with research showing that people who get brighter morning light naturally go to sleep earlier and experience less daytime sleepiness. Studies reveal that the timing, intensity, and duration of light exposure throughout the day create a “light signature” that influences circadian rhythms and sleep-wake patterns. Those with high morning light exposure and low evening light exposure show optimal sleep timing and alertness patterns, while the reverse pattern is associated with delayed sleep and increased daytime sleepiness.

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Room Light Before Bedtime Suppresses Melatonin: Extended Analysis of Light Exposure Effects

Tags: Light Exposure, Melatonin Suppression, Circadian Rhythm, Sleep Onset, Bedtime Lighting

October 22, 2025

How Much Does Room Light Before Bedtime Actually Suppress Melatonin Production?

Extended analysis reveals that even moderate room light exposure before bedtime significantly suppresses melatonin production in a dose-dependent manner, with profound effects on sleep onset and circadian timing. The research found that typical indoor lighting levels (150-200 lux) suppress melatonin production by 50-70% within 2 hours of exposure, while brighter room lighting (300+ lux) can suppress melatonin by up to 90%. Even relatively dim lighting (50-100 lux) reduces melatonin production by 20-30%, demonstrating that the human circadian system is exquisitely sensitive to light exposure during the evening hours. The study reveals that melatonin suppression begins within 15 minutes of light exposure and persists for 1-2 hours after lights are turned off, significantly delaying sleep onset and disrupting natural circadian rhythms.

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