What you've heard
Blue-blocking glasses protect your sleep from screens
Verdict
Mostly unsupported; skip the glasses unless a clinician suggests them for a specific sleep problem
Do blue-blocking glasses protect your sleep?
Mostly unsupported; skip the glasses unless a clinician suggests them for a specific sleep problem.
A Cochrane review found that blue-filtering lenses may do nothing for eye strain from computer use, and could not say whether they help sleep, because the evidence was of very low certainty. Amber lenses showed mixed results, with a possible benefit in specific sleep or mood disorders. A National Sleep Foundation panel could not agree that the light from screens before bed harms sleep, and found that filtering blue light gave "only minimal improvements." Brightness and timing matter more than color, and dimming the room does the same job for nothing.9 Screens do disturb sleep in other ways, especially for children and teenagers (Chapter 12).
Where the book tests it
What the book recommends instead
Get outdoor daylight early in your day, roughly 10 to 30 minutes
ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.How: within an hour of waking, step outside, not behind glass: walk part of the commute, coffee on the step, the dog. Longer when gray or shaded; open sky beats a courtyard; a lunchtime walk outside counts too. Sunglasses are fine. Why: morning light pulls the clock earlier, and outdoors is many times brighter than indoors.
Sources
- 9.Singh, S., Keller, P.R., Busija, L., McMillan, P., et al. (2023). "Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults." Cochrane Database of Systematic Reviews, 8(8), CD013244. https://doi.org/10.1002/14651858.CD013244.pub2 (Seventeen trials.) ; Shechter, A., Quispe, K.A., Mizhquiri Barbecho, J.S., Slater, C., et al. (2020). "Interventions to reduce short-wavelength ('blue') light exposure at night and their effects on sleep: a systematic review and meta-analysis." Sleep Advances, 1(1), zpaa002. https://doi.org/10.1093/sleepadvances/zpaa002 ; Hartstein, L.E., Mathew, G.M., Reichenberger, D.A., Rodriguez, I., et al. (2024). "The impact of screen use on sleep health across the lifespan: A National Sleep Foundation consensus statement." Sleep Health, 10(4), 373-384. https://doi.org/10.1016/j.sleh.2024.05.001
Note numbers are those of Chapter 7, Light and Dark.
This verdict is one of the "What you've heard" boxes in Chapter 7, Light and Dark, where the book tests the claims people repeat against the studies behind them.
Educational content, not medical advice. Disclaimer.