What is Circadian Rhythm

Circadian rhythms are natural physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes exist in most living organisms and respond primarily to light and darkness.

Science Behind Optimizing

Circadian Rhythm for Better Sleep

The scientists believe that your sleep is mostly regulated by circadian rhythm and sleep pressure. These two work seamlessly together to help us fall asleep, stay asleep, and wake up after a restorative sleep. When the circadian rhythm is out of sync, we suffer from poor sleep, such as difficulty falling asleep, waking up frequently in the middle of sleep, waking up earlier than we want, or waking up feeling groggy.

Therefore, having a dialed circadian clock is the foundation for a good night’s sleep. 
Poster

Light Therapy for Circadian Rhythm

The effectiveness of light therapy lies in its ability to stimulate photoreceptors in the eyes, particularly those sensitive to blue light, which send signals to the brain, influencing the production of melatonin and other hormones that regulate sleep and wakefulness. By carefully managing exposure to light,light therapy can be a valuable tool in addressing circadian rhythm misalignment and promote healthy sleep. 

Research behind Lumos

Research from Stanford University has shown that brief light flashes can effectively regulate the human circadian clock. The Lumos Mask has also been tested in multiple double-blind, placebo-controlled studies, both in the lab—using biomarkers to confirm circadian clock regulation—and in real-world settings with healthy night-shift workers.

Selected publications 

Lok R, Duran M, Zeitzer JM (2023) Moving time zones in a flash with light therapy during sleep. Scientific Reports 13:14458. PMCID: PMC10475014


Joyce D, Spitschan M, Zeitzer JM (2022) Optimizing light flash sequence duration to shift human circadian phase. Biology 11(12):1807. PMCID: PMC9775356


Joyce DS, Spitschan M, Zeitzer JM (2022) Duration invariance and intensity dependence of the human circadian system phase shifting response to brief light flashes. Proceedings B 289: 20211943. PMCID: PMC8905166


Gabel V, Miglis M, Zeitzer JM (2020) Effect of artificial dawn light on cardiovascular function, alertness, and balance in older adults. Sleep 43(10):zsaa082.


Kaladchibachi S, Negelspach DC, Zeitzer JM, Fernandez F (2019) Optimization of circadian responses with shorter and shorter millisecond flashes. Biology Letters 15: 20190371. PMCID: PMC6731482


Najjar RP, Zeitzer JM (2016) Temporal integration of light flashes by the human circadian system. Journal of Clinical Investigation 126: 938-947. PMCID: PMC4767340


Zeitzer JM, Fisicaro RA, Ruby NF, Heller HC (2014) Millisecond flashes of light phase delay the human circadian clock during sleep. Journal of Biological Rhythms 29:370-376. PMCID: PMC5056587


Zeitzer JM, Ruby NF, Fisicaro RA, Heller HC (2011) Response of the human circadian system to millisecond flashes of light. PLoSOne 6: e22078. PMCID: PMC3132781


Kaplan KA, Mashash M, Williams R, Batchelder H, Star-Glass L, Zeitzer JM (2019) Effect of light flashes vs sham therapy during sleep with adjunct cognitive behavioral therapy on sleep quality among adolescents: a randomized clinical trial. JAMA Network Open 2: e1911944. PMCID: PMC6763980