Dim light in the evening
Lower light intensity in the last hours before bed so the clock can wind down.
Key takeaways
- What it is: Lower light intensity in the last hours before bed so the clock can wind down.
- Why it works: Light in the evening delays the circadian clock and suppresses melatonin, the hormone that signals biological night. Bright artificial light after dusk effectively tells the brain it is still daytime, pushing your sleep window later and blunting the nighttime melatonin rise.
- Evidence: Backed by randomized trials / meta-analyses.
- Avoid: Trusting a blue-light filter while leaving bright overhead lights on — total light intensity is the main driver, not screen color alone.
Why it works
Light in the evening delays the circadian clock and suppresses melatonin, the hormone that signals biological night. Bright artificial light after dusk effectively tells the brain it is still daytime, pushing your sleep window later and blunting the nighttime melatonin rise.
How to do it
- 1Drop overall light levels for the last hour or two before bed — fewer, dimmer, lower lamps.
- 2Favor warm, low light over bright overhead lighting in the evening.
- 3Keep the bedroom dark for sleep; even small light sources can intrude.
What the evidence says
RCT / meta-analysisEvening light exposure delaying circadian phase and suppressing melatonin is well documented; brighter evening light produces larger melatonin suppression and phase delay.
Honest caveat: The dominant lever is overall light intensity and timing, not just screen "blue light"; reducing total brightness matters more than the color filter alone.
- — Gooley et al. (2011), exposure to room light suppresses melatonin, J. Clinical Endocrinology & Metabolism
Common mistake
Trusting a blue-light filter while leaving bright overhead lights on — total light intensity is the main driver, not screen color alone.
IX Coach turns evening dimming into a concrete wind-down cue and helps you build the environment changes (not just app filters) that actually move the clock.
Practice this with IX Coach →