Our approach

The science of
your rhythm

Everything we make starts from one fact: your body runs on a 24-hour clock, and light is how you set it. Here is the science — and the research behind every claim.

We would rather show you the evidence than sell you a promise. Below is how the circadian system actually works, what it needs across the day, and exactly how strong the science is behind each of our products.

NightDawnMorningMiddayEveningDuskNight

About 16 hours awake · 8 hours asleep — one long day, one consolidated night

01 / The clock

You run on a 24-hour clock

Deep in the brain, a master clock called the suprachiasmatic nucleus keeps your whole body on a daily cycle. In tightly controlled studies, its natural period averages about 24.2 hours — remarkably precise.1

That clock, working with your build-up of sleep pressure, is what shapes the familiar pattern of roughly 16 hours awake and 8 asleep — letting you stay alert in one long stretch and sleep in one consolidated block.2

24.2hoursNatural clock period
16hoursAwake, in one stretch
8hoursConsolidated sleep

02 / The switch

Light is the master switch

Of everything that keeps your clock aligned to the day, light is the most powerful — a stronger daily synchroniser than meal timing or exercise.3

Your eye carries a dedicated light-sensing pigment, melanopsin, not in the rods and cones you see with, but in a special class of inner-retina cells.4 These cells respond to light entirely on their own5 and wire directly to the master clock — a private line carrying “how bright is it?” straight to your body’s timekeeper.6

Well-established
Close-up of an eye catching cool light

03 / Morning

Set the clock: bright & cool

Bright light in the morning nudges your clock a little earlier and anchors it to the day.7 That morning setting is what times your body’s natural evening rise in melatonin, a dozen-plus hours later — so a well-lit morning helps you wind down on schedule at night.8

In a workweek study, a bright morning left people more alert and less groggy, with more efficient nights’ sleep.9 People with more day light and less night light also report better mood.10

Aurelia’s circadian lamp is built for exactly this: bright, cool morning light at your desk or mirror.

Well-established
Cool morning light over a desk

04 / The numbers

How much light, and when

In 2022, a panel of the world’s leading circadian scientists published clear targets for indoor light — measured in melanopic EDI, the unit set by the international CIE S 026 standard for how much your body clock actually “sees.”11,12

250lux mEDI, minimumDaytime
10lux mEDI, maximum3 h before bed
1lux mEDI, maximumWhile you sleep

Ordinary indoor light is far dimmer than daylight — dark winter mornings and windowless offices routinely miss the daytime target.11

05 / Evening

Wind down: dim & warm

Ordinary room light in the hours before bed pushes back your natural melatonin rise and shrinks the window for restful sleep.13 Reading on a bright, blue-lit screen makes it take longer to fall asleep and blunts next-morning alertness.14

This is why our lamp shifts to a dim, warm evening mode. On amber blue-blocking glasses, we are honest: an early study saw a modest gain of about 28 minutes more sleep15, while the largest evidence review to date finds the broader case for blue-light glasses still unresolved.16

Evening light: established · glasses: emerging
Warm, dim evening light while reading

06 / Night

Sleep: dark, quiet, cool

Dark. Even a moderate light left on overnight was linked to a higher heart rate and reduced next-morning insulin sensitivity — the body handled a glucose challenge less efficiently.17 A true blackout matters.

Quiet. Night-time noise fragments sleep as sound peaks rise18; in noisy settings, earplugs and an eye mask measurably improved how people slept.19

Cool. Falling asleep depends on your core temperature drifting down, so a cooler surface and room ease you into sleep20; a warm bath 1–2 hours before bed speeds this along.21

Well-established
Sleeping in a blackout mask in near-total darkness

07 / The system

How each product maps to the evidence

We grade our own products. Where the science is strong we say so — and where it is still early, we say that too.

ProductWhat it’s forEvidence
Circadian Lamp · cool modeBright morning light to set the clockWell-established
Circadian Lamp · warm modeDim, warm evening lightWell-established
Blackout MaskNear-total darkness for sleepWell-established
Sleep EarplugsReduce sleep-fragmenting noiseWell-established
Cooling PillowHelp core temperature dropWell-established
Night GlassesCut bright, blue evening lightEmerging
Red Light PanelRecovery & wellbeingEmerging

References

Peer-reviewed sources, most recent research prioritised. Aurelia products are general wellness devices, not medical devices, and are not intended to diagnose, treat, cure or prevent any disease.

  1. Czeisler CA, Duffy JF, Shanahan TL, et al. Stability, precision, and near-24-hour period of the human circadian pacemaker. Science. 1999. doi:10.1126/science.284.5423.2177
  2. Dijk DJ, Czeisler CA. Contribution of the circadian pacemaker and the sleep homeostat to sleep propensity, sleep structure… The Journal of Neuroscience. 1995. doi:10.1523/JNEUROSCI.15-05-03526.1995
  3. Duffy JF, Wright KP Jr. Entrainment of the human circadian system by light. Journal of Biological Rhythms. 2005. doi:10.1177/0748730405277983
  4. Provencio I, Rodriguez IR, Jiang G, et al. A novel human opsin in the inner retina. The Journal of Neuroscience. 2000. doi:10.1523/JNEUROSCI.20-02-00600.2000
  5. Berson DM, Dunn FA, Takao M. Phototransduction by retinal ganglion cells that set the circadian clock. Science. 2002. doi:10.1126/science.1067262
  6. Hattar S, Liao HW, Takao M, Berson DM, Yau KW. Melanopsin-containing retinal ganglion cells: architecture, projections, and intrinsic photosensitivity. Science. 2002. doi:10.1126/science.1069609
  7. Ohashi M, Eto T, Takasu T, Motomura Y, Higuchi S. Circadian phase delay without morning light and phase advance by bright light exposure the following morning. Clocks & Sleep. 2023. doi:10.3390/clockssleep5040041
  8. Blume C, Garbazza C, Spitschan M. Effects of light on human circadian rhythms, sleep and mood. Somnologie. 2019. doi:10.1007/s11818-019-00215-x
  9. He M, Ru T, Li S, Li Y, Zhou G. Morning bright light improves nocturnal sleep and next-morning alertness among college students. Journal of Sleep Research. 2023. doi:10.1111/jsr.13724
  10. Siraji MA, Spitschan M, Kalavally V, Haque S. Light exposure behaviors predict mood, memory and sleep quality. Scientific Reports. 2023. doi:10.1038/s41598-023-39636-y
  11. Brown TM, Brainard GC, Cajochen C, et al. Recommendations for daytime, evening, and night-time indoor light exposure. PLoS Biology. 2022. doi:10.1371/journal.pbio.3001571
  12. International Commission on Illumination. CIE S 026/E:2018 — System for metrology of optical radiation for ipRGC-influenced responses to light. CIE, Vienna. 2018. doi:10.25039/S026.2018
  13. Gooley JJ, Chamberlain K, Smith KA, et al. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration. The Journal of Clinical Endocrinology & Metabolism. 2011. doi:10.1210/jc.2010-2098
  14. Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. PNAS. 2015. doi:10.1073/pnas.1418490112
  15. Shechter A, Kim EW, St-Onge MP, Westwood AJ. Blocking nocturnal blue light for insomnia: a randomized controlled trial. Journal of Psychiatric Research. 2018. doi:10.1016/j.jpsychires.2017.10.015
  16. Singh S, Keller PR, Busija L, et al. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews. 2023. doi:10.1002/14651858.CD013244.pub2
  17. Mason IC, Grimaldi D, Reid KJ, et al. Light exposure during sleep impairs cardiometabolic function. PNAS. 2022. doi:10.1073/pnas.2113290119
  18. World Health Organization Regional Office for Europe. Night Noise Guidelines for Europe. 2009. who.int
  19. Hu RF, Jiang XY, Hegadoren KM, Zhang YH. Effects of earplugs and eye masks combined with relaxing music on sleep in the intensive care unit. Critical Care. 2015. doi:10.1186/s13054-015-0855-3
  20. Okamoto-Mizuno K, Mizuno K. Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology. 2012. doi:10.1186/1880-6805-31-14
  21. Haghayegh S, Khoshnevis S, Smolensky MH, Diller KR, Castriotta RJ. Before-bedtime passive body heating… a systematic review and meta-analysis. Sleep Medicine Reviews. 2019. doi:10.1016/j.smrv.2019.04.008

Rest, engineered — and evidenced.

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