Set a screen curfew 60-90 minutes before sleep
All screens off 60-90 minutes before intended sleep time — including television.
Key takeaways
- What it is: All screens off 60-90 minutes before intended sleep time — including television.
- Why it works: Melatonin secretion begins approximately 2 hours before habitual sleep time. Blue-spectrum light (480nm wavelength, dominant in LED/LCD screens) suppresses melatonin via ipRGC retinal cells and delays the melatonin onset by up to 90 minutes at typical screen brightnesses. This delays sleep onset and can phase-shift the circadian rhythm over successive nights.
- Evidence: Backed by randomized trials / meta-analyses.
- Avoid: Using a blue-light filter app and continuing to scroll until midnight, assuming the filter fully negates the melatonin suppression — it reduces but does not eliminate the effect, and does nothing about conditioned arousal.
Why it works
Melatonin secretion begins approximately 2 hours before habitual sleep time. Blue-spectrum light (480nm wavelength, dominant in LED/LCD screens) suppresses melatonin via ipRGC retinal cells and delays the melatonin onset by up to 90 minutes at typical screen brightnesses. This delays sleep onset and can phase-shift the circadian rhythm over successive nights.
How to do it
- 1Set a phone alarm 90 minutes before your target sleep time labelled "all screens off."
- 2At the alarm, close the laptop, turn off the TV, and put the phone on charge outside the bedroom.
- 3Replace the screen time with low-arousal activity: reading a physical book, stretching, light conversation, bath.
- 4After two weeks, track whether sleep onset improves on nights when you comply versus nights when you don’t.
What the evidence says
RCT / meta-analysisLaboratory studies confirm that blue-light exposure in the 60-90 minutes before sleep delays melatonin onset and increases sleep latency. The effect is dose-dependent on light intensity and timing.
Honest caveat: Chang et al. used e-readers at maximum brightness over five nights; effect sizes from casual real-world phone use may be smaller. Blue-light glasses show inconsistent benefits in trials — device removal is more reliable.
- — Chang et al. (2015), evening use of light-emitting eReaders negatively affects sleep, PNAS
Common mistake
Using a blue-light filter app and continuing to scroll until midnight, assuming the filter fully negates the melatonin suppression — it reduces but does not eliminate the effect, and does nothing about conditioned arousal.
IX Coach adds the screen curfew to your evening routine sequence and sends a gentle prompt at the curfew time — appearing as a notification before all notifications end for the evening.
Practice this with IX Coach →