Avoid intense light sources, especially those placed high up, between 10:00 PM and 4:00 AM to preserve sleep quality, by prioritizing low-level, dimmed, or red-colored lighting.

noli's read

This recommendation is based on solid chronobiology principles regarding the regulation of our internal clock. Indeed, a clinical study by Gooley and his team (2011) demonstrated that the artificial light in our rooms during the evening delays and suppresses the production of melatonin, the sleep hormone. The idea of avoiding lighting placed high up is also logical, because our ocular receptors sensitive to brightness are more concentrated in the lower part of the retina. Regarding red light, a randomized controlled trial conducted by Zhao and his collaborators in 2012 confirmed that it did not hinder melatonin and could even improve the perception of sleep quality in athletes. Nevertheless, a controlled study from 2026 suggests that for some people, direct exposure to red light before bedtime may prove slightly stimulating compared to total darkness. In short, limiting bright lights during this window is scientifically validated, even if total darkness remains preferable to any colored lighting.

the sources

1. 1NIH Office of Dietary Supplements 2026
2. 2Manson JE et al. 2019
3. 3Bhatt DL et al. 2019
4. 4Khan SU, Lone AN, Khan MS, et al. 2021
5. 5Liao Y, Xie B, Zhang H, et al. 2019
6. 6hubermanprotocols.com (fan reference guide)