Does better light make you feel better and sleep deeper?
Effect of daylight LED on visual comfort, melatonin, mood, waking performance and sleep
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Delta EEG activity increased after daylight-LED exposure, but melatonin levels didn’t change.
Most research links improved sleep to melatonin regulation, so seeing deeper sleep without melatonin shifts challenges the assumption that melatonin is the main driver of sleep quality.
Practical Takeaways
Consider using daylight-spectrum LED bulbs with high color rendering index (CRI) and melanopic strength in workspaces or homes during the day.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Delta EEG activity increased after daylight-LED exposure, but melatonin levels didn’t change.
Most research links improved sleep to melatonin regulation, so seeing deeper sleep without melatonin shifts challenges the assumption that melatonin is the main driver of sleep quality.
Practical Takeaways
Consider using daylight-spectrum LED bulbs with high color rendering index (CRI) and melanopic strength in workspaces or homes during the day.
Publication
Journal
Lighting Research & Technology
Year
2019
Authors
Christian Cajochen, M. Freyburger, T. Basishvili, T. Basishvili, C. Garbazza, F. Rudzik, C. Renz, Kumpei Kobayashi, Yasuhiro Shirakawa, Oliver Stefani, J. Weibel
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Claims (4)
Being around blue light at night, like from phones or screens, might keep your body from making the sleep hormone melatonin because it keeps stress hormone levels high, making it harder to fall and stay asleep.
Using a special kind of bright white LED light that looks more like natural daylight might make young guys feel more awake, comfortable, and in a better mood during the day—even if it’s just as bright as regular office lighting.
If young, healthy guys are exposed to daylight-like LED lights during the day, they might sleep more deeply at night — even if their alertness and sleep hormone levels don’t change much.
In healthy young guys, better-quality daylight-like LED lights don’t seem to change daily melatonin levels or brain performance like focus and memory — so upgrading light quality might not always boost health or thinking skills.