In November 2013, Owaves argued that electric light at night could join cigarettes, trans fats and soda as something once thought harmless and later tied to disease. Since then, the 2017 Nobel Prize explained how body clocks work, and studies of up to 88,905 people link brighter nights with worse health.
Key takeaways
- On 23 November 2013, Owaves published the essay Cigarettes, Trans Fats and Light Bulbs, arguing that artificial light at night and the 24/7 screen life it enables disrupt the body clock.
- In 2017, Jeffrey C. Hall, Michael Rosbash and Michael W. Young won the Nobel Prize in Physiology or Medicine for discovering the molecular mechanisms that control the circadian rhythm.
- A 2022 laboratory study of 20 young adults found that one night of sleep with room lighting (100 lux) raised night-time heart rate and next-morning insulin resistance compared with a dim room.
- A 2022 expert consensus in PLOS Biology recommends bright daytime light, dim light for at least 3 hours before bed, and a sleep environment as dark as possible.
- Owaves: My BodyClock now plans all 24 hours on one circle, and its 2026 release notes add sunrise, sunset and Time in Daylight to shared days.
What did Owaves argue in 2013?
In November 2013, about six months before its first app launched, Owaves argued that the light bulb might be the next everyday invention people trusted and science later showed to be harmful. The essay, by founder and CEO Royan Kamyar, M.D., MBA, set it beside cigarettes, trans fats and soda. In our own words:
- Light changed the day. Electric light, then phones, made a 24/7 lifestyle possible.
- We evolved with the sun. “Human beings evolved in an environment guided by the rise and fall of the sun.” Sleep, hormones and metabolism grew up around that pattern.
- Food timing matters. It cited mouse research from Satchin Panda’s lab at the Salk Institute and a Harvard study of nearly 27,000 men on late-night eating: “When you eat may be just as important as what you eat.”
- Shift workers as a warning. People who stay up with screens, it said, become “social shift workers.”
- A public-health call. It closed by calling for public awareness, suggesting that 3 AM texts, calls and emails be labeled second-hand insomnia.
Several studies it leaned on were in mice, and its human evidence was mostly observational: links, not proof of harm.
What has science learned about body clocks since 2013?
In 2017, Hall, Rosbash and Young won the Nobel Prize in Physiology or Medicine for discovering the molecular mechanisms controlling the circadian rhythm. In fruit flies, they found a gene whose protein builds up in the cell at night and breaks down by day, a self-sustaining clock that works on the same principles in human cells. The Nobel press release added that there are indications that chronic misalignment between lifestyle and the inner clock is associated with increased risk for various diseases.
Is light at night bad for you?
Light at night is linked with poorer sleep and health markers, and one lab study shows a short-term effect, but long-term harm in people rests on associations.
| Year | Study | Design and size | What it found |
|---|---|---|---|
| 2022 | Mason et al., PNAS | Randomized laboratory study, 20 healthy adults aged 18–40, two parallel groups of 10 | After one night of sleep with 100 lux overhead room light, night-time heart rate and next-morning insulin resistance were higher than in the group that slept under 3 lux |
| 2022 | Brown et al., PLOS Biology | Expert scientific consensus | Daytime light of at least 250 lux (melanopic EDI) at the eye; at most 10 lux from 3 hours before bed; at most 1 lux during sleep |
| 2024 | Windred et al., PNAS | Prospective study, 88,905 UK Biobank adults wearing light sensors for a week, about 8 years of follow-up | Brighter nights were associated with higher all-cause mortality risk, brighter days with lower risk |
The Mason study comes closest to cause and effect, since it changed only the light in the room, but it was small and lasted one night. Northwestern Medicine, which ran it, advised people to close the blinds and keep lights off during sleep.
The Windred study is observational. People with the brightest nights (top 10%) had about 21–34% higher all-cause mortality risk than the darker half, and those with the brightest days about 17–34% lower risk, in models adjusted for age, sex, ethnicity, photoperiod, and sociodemographic and lifestyle factors. That is an association, not proof.
In its Monographs Volume 124, published in 2020, the International Agency for Research on Cancer classified night shift work as probably carcinogenic to humans (Group 2A). Night shifts involve far more than light, so this is not a verdict on light bulbs; see our night shift schedule.
What did the 2013 essay get right, and what did it overstate?
The direction held up: light is a timing signal, and daylight by day with darkness at night is now consensus advice. The strongest lines went further than the evidence: calling the light bulb potentially toxic, or guessing its toll might outweigh cigarettes, trans fats and soda combined, remains unproven. Light is double-edged, since bright days are linked with better outcomes. More in whether electric light makes us sleep later and whether kids should sleep with the light on.
What does the Owaves app do now?
Owaves turned the essay into a planner. On 8 May 2014, it launched an iPad wellness planner with a 24-hour clock oriented to local sunrise and sunset (when Owaves launched). As of November 2026, per the App Store listing and owaves.com:
- My BodyClock shows all 24 hours as one circle, so sleep, meals and wind-down sit beside work.
- The sun on your day. Version 8.0 shares any day as an image with sunrise, sunset and Time in Daylight; version 8.1 (September 2026) brought more accurate sunset times.
- Apple Health compares planned and actual activities (how to connect it).
- BodyClock Plus adds daily Deep Sleep, Deep Work, Peak Fitness and Eating Windows recommendations (how to use Windows).
- BodyClock Score gives a daily 0–100 view of circadian alignment.
- Owaves is free on iPhone, iPad and Apple Watch and reports 1.3M+ downloads.
Your day on My BodyClock
The day above on My BodyClock puts the 2022 light advice into hours: a walk outside shortly after waking, deep work near a window, lunch outdoors and an early dinner at 6 PM, true to the essay’s point about meal timing. From 8 PM the lamps go low and screens go away. Sleep runs from 10:30 PM to 6:30 AM in a dark room.
Take the Body Clock Quiz to find your Body Clock Type, then plan a day like this free in Owaves on the App Store. On Android, join the waitlist.
FAQ
Is light at night bad for your health?
Bright light at night is linked with poorer sleep and with worse health outcomes in large observational studies, such as a 2024 UK Biobank analysis of 88,905 adults. A 2022 lab study of 20 young adults showed one night of room light during sleep raised heart rate and next-morning insulin resistance. Long-term harm in people is still an association.
How dim should lights be before bed?
A 2022 expert consensus in PLOS Biology recommends no more than 10 lux (melanopic EDI) at the eye starting at least 3 hours before bedtime, and no more than 1 lux during sleep. In practice, that means low, warm lamps in the evening and a dark bedroom.
What did Owaves say about light bulbs in 2013?
In a 23 November 2013 essay, Owaves compared the light bulb with cigarettes, trans fats and soda, things once seen as harmless and later linked to disease. It argued that artificial light and always-on screens disrupt the body clock and called for public awareness.
Does Owaves track light exposure?
No light sensor is described in the App Store listing. Owaves plans your day on My BodyClock, compares planned and actual activities through Apple Health, and shared days can show sunrise, sunset and Time in Daylight.
Sources
- Royan Kamyar, M.D., MBA (Owaves). “Cigarettes, Trans Fats and Light Bulbs.” owaves.com, 23 November 2013. https://owaves.com/cigarettes-trans-fats-light-bulbs/
- Nobel Assembly at Karolinska Institutet. “The 2017 Nobel Prize in Physiology or Medicine — Press release.” 2 October 2017. https://www.nobelprize.org/prizes/medicine/2017/press-release/
- Brown TM, Brainard GC, Cajochen C, Czeisler CA, et al. “Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults.” PLOS Biology, 17 March 2022. doi:10.1371/journal.pbio.3001571. https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001571
- Mason IC, Grimaldi D, Reid KJ, Warlick CD, et al. “Light exposure during sleep impairs cardiometabolic function.” PNAS, 14 March 2022. doi:10.1073/pnas.2113290119. https://pmc.ncbi.nlm.nih.gov/articles/PMC8944904/
- Northwestern University via ScienceDaily. “Close the blinds during sleep to protect your health.” 14 March 2022. https://www.sciencedaily.com/releases/2022/03/220314154355.htm
- Windred DP, Burns AC, Lane JM, Olivier P, et al. “Brighter nights and darker days predict higher mortality risk: A prospective analysis of personal light exposure in >88,000 individuals.” PNAS, 15 October 2024. doi:10.1073/pnas.2405924121. https://doi.org/10.1073/pnas.2405924121
- International Agency for Research on Cancer. “IARC Monographs Volume 124: Night Shift Work.” 2 June 2020. https://www.iarc.who.int/news-events/iarc-monographs-volume-124-night-shift-work/
- Owaves via PR Newswire. “Owaves Launches World’s First Wellness Planner.” 8 May 2014. https://www.prnewswire.com/news-releases/owaves-launches-worlds-first-wellness-planner-258452291.html
- Apple App Store. “Owaves: My BodyClock” (US listing, version history). Accessed 5 November 2026. https://apps.apple.com/us/app/owaves-worlds-first-wellness/id869648628
- Owaves. “The visual calendar for a healthier day” (home page). Accessed 5 November 2026. https://owaves.com/
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