Bright light can delay sleep
Ordinary room light before bed can suppress melatonin and delay when your body feels ready for sleep.
THE SCIENCE
The Science Behind Better Evenings.
Your brain uses light to decide whether to stay alert or wind down. Here’s what changes — and why warm, low light matters.
HOW IT WORKS
How light sets your body clock.
Eyes read the light. Your body clock interprets it. Your evening rhythm follows.
Simple. Powerful. Backed by science.
Every claim starts with this mechanism.
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Your eyes read the light.
Special receptors in your eyes report the brightness and colour of the light around you.
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Your brain decides what time it is.
That signal reaches your body clock, helping it judge whether it is daytime or time to wind down.
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Your body follows.
Bright evening light can delay melatonin timing. Dim, warm light is a gentler signal at the end of the day.
References Berson et al., Science 2002 — ipRGC discovery (opens in a new tab) LeGates et al., Nat Rev Neurosci 2014 — review (opens in a new tab)
THE BRIGHTEST ROOM
The last light you see is often the harshest.
Bathroom lighting is designed for grooming: bright, cool and overhead. That makes the last room before bed one of the simplest places to create a gentler evening signal.
Bright, cool-toned and overhead — closer in character to midday sun than to evening light.
Dimmer and warmer in tone, so the room reads as evening rather than as the middle of the day.
Source: Brown et al., PLoS Biology 2022 — expert consensus on indoor light (opens in a new tab)
WHAT THE RESEARCH SAYS
Three things worth knowing.
Dim + warm is gentler
Your body clock is especially sensitive to short-wavelength light. Lower brightness and a warmer tone work together.
Consistency makes it easier
A repeatable evening cue is easier to keep than a complicated routine. The value is in doing it regularly.
MYTH VS REALITY
What people get wrong about winding down.
Myth
Sleep only begins in bed.
Reality
Your brain starts preparing earlier. Evening light is one of the signals it uses to set the timing.
Source: Gooley et al., JCEM 2011 — room light before bed (opens in a new tab)
Myth
Any dim light is fine.
Reality
Brightness and spectrum both matter. Dimmer, warmer light generally produces a gentler evening signal than bright, cool light.
Source: Brainard et al., J Neurosci 2001 — action spectrum (opens in a new tab)
WHERE HUSH GLOW FITS
One small change to the last hour of your day.
Hush Glow® is not a treatment or a sleep device. It simply lets you switch off the overhead and keep the last room of your day warm, low and comfortable. The routine is the point; the lamp makes it easier to keep.
- Warm amber tone
- Low brightness
- No overhead glare
REFERENCES
Check every claim yourself.
Every claim on this page links to the specific paper behind it — not to an organisation's homepage. Identifiers are printed so you can verify each one independently.
- Phototransduction by retinal ganglion cells that set the circadian clockThe discovery that the eye contains photoreceptors whose job is timekeeping rather than vision. Supports “your eyes read the light”. (opens in a new tab)
- Light as a central modulator of circadian rhythms, sleep and affectReview of how light signals reach the body clock and set its timing. Supports the three-step mechanism section. (opens in a new tab)
- Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humansControlled human trial: ordinary room light (<200 lux) before bed suppressed melatonin versus dim light. The primary citation for the melatonin claim. (opens in a new tab)
View all studies and references
- Association between nocturnal light exposure and melatonin in humans: a meta-analysisMeta-analysis pooling human studies of night-time light and melatonin, rather than any single trial. (opens in a new tab)
- Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptorEstablishes which wavelengths suppress melatonin most — the basis for warm light being the gentler evening choice. (opens in a new tab)
- An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humansIndependent action spectrum published the same year, reaching the same short-wavelength peak. (opens in a new tab)
- High sensitivity of human melatonin, alertness, thermoregulation, and heart rate to short wavelength lightHuman trial comparing short- against long-wavelength evening light on melatonin and alertness. (opens in a new tab)
- The effects of spectral tuning of evening ambient light on melatonin suppression, alertness and sleepDirectly tests warm versus blue-enriched ambient light in the evening — the closest study to what this product changes. (opens in a new tab)
- Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adultsExpert consensus statement recommending low melanopic light in the hours before bed. The strongest single citation on this page. (opens in a new tab)
- Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertnessRandomised crossover trial showing evening light delayed circadian timing and next-day alertness. (opens in a new tab)
- Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timingLinks day-to-day irregularity with later measured circadian phase. Supports the consistency claim (observational). (opens in a new tab)
This page is general information about lighting and evening routines. It is not medical advice, and Hush Glow® is not a medical device — it does not diagnose, treat or prevent any condition, including insomnia or any other sleep disorder. If you're concerned about your sleep, please speak to a qualified healthcare professional.
Make the last light gentler.
One lamp. One easy cue. A warmer, lower-lit end to your day.
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