Blue Light Exposure Timing

## Observation Log - Blue Light Protocol ### Context Testing optimal blue light exposure windows for circadian entrainment without compromising evening melatonin production. ### Protocol Week 1: Morning only (06:00-08:00) Week 2: Morning + Midday (06:00-08:00, 12:00-13:00) Week 3: Throughout day until 16:00 Week 4: Throughout day until 19:00 ### Findings 1. **Morning Only**: Strong morning alertness, excellent evening sleepiness. Melatonin onset ~21:00. 2. **Morning + Midday**: Eliminated post-lunch dip. No significant impact on evening melatonin. 3. **Until 16:00**: Sustained alertness throughout workday. Melatonin onset delayed by ~30 minutes. 4. **Until 19:00**: Significant melatonin suppression. Sleep onset delayed by 2+ hours. Reduced sleep quality. ### Optimal Protocol Blue light exposure from wake until 16:00, with emphasis on morning hours (480nm, 10,000 lux equivalent). After 16:00, strict blue light filtering (f.lux setting 2700K). ### Additional Notes - Individual variation significant (chronotype dependent) - Light intensity matters more than duration - Outdoor light exposure superior to artificial sources