Table Of Contents
-
Key Highlights
- What is Circadian Light? Exploring the Science Behind It
- How Circadian Light Influences Melatonin and Sleep
- Measuring Circadian Light: Technologies and Protocols
- Practical Applications of Circadian Lighting in Homes and Workplaces
- Circadian Light and Health: Benefits and Risks
-
Frequently Asked Questions About Circadian Light
-
Conclusion: Harnessing Circadian Light for Better Health
-
References
Key Highlights
- Circadian light is a specific type of optical radiation that influences the human circadian system, distinct from light perceived visually
- The circadian system is primarily regulated by ipRGCs containing melanopsin, sensitive to short-wavelength (blue) light but also influenced by cones via spectral opponency
- Melatonin suppression by light is wavelength and intensity dependent, with blue light having the strongest effect
- Circadian light can be quantified using models like the Rea et al. phototransduction model, producing metrics such as CL, CLA, and CS
- Practical circadian lighting mimics natural daylight cycles, using cool blue tones during the day and warm amber hues in the evening to support health
- Circadian lighting protocols, such as the UC Davis Circadian Protocol, are being applied in healthcare and residential settings to improve sleep, mood, and safety
- Emerging research reveals complex retinal circuits that integrate color and irradiance signals to regulate circadian rhythms and mood
What is Circadian Light? Exploring the Science Behind It
Most people understand that light helps us see, but fewer realize that light also serves a completely separate biological function: regulating our internal circadian clock. Circadian light refers to the specific characteristics of optical radiation that influence our body’s 24-hour rhythms, including sleep-wake cycles, hormone production, and metabolic processes.1
Unlike visual light, which enables us to perceive our environment through rod and cone photoreceptors, circadian light operates through a distinct pathway involving specialized cells in the retina called intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells contain a photopigment called melanopsin, which is most sensitive to blue light wavelengths around 480 nanometers.
The Photoreceptors Behind Circadian Regulation
The circadian system relies on a sophisticated network of photoreceptors working in concert:
- Melanopsin-containing ipRGCs: These specialized ganglion cells act as the primary circadian photoreceptors, responding directly to light even in the absence of traditional rod and cone input
- Cone photoreceptors: Through spectral opponency mechanisms, cones modulate the circadian response by comparing signals from different wavelengths of light
- Rod photoreceptors: At lower light levels, rods contribute to circadian signaling through their connections to ipRGCs
Recent research from the University of Washington has revealed that color vision circuits in the retina, involving specialized amacrine cells, play a crucial role in communicating light information to ipRGCs. This discovery challenges previous assumptions about how circadian rhythms are regulated, showing that the system integrates both brightness and color information.
Understanding Spectral Sensitivity
The circadian system exhibits subadditivity, meaning that combining different wavelengths of light does not simply add up their individual effects. Instead, the system uses spectral opponency—comparing signals between short-wavelength (blue) and longer-wavelength (yellow-green) light—to more accurately detect natural daylight and distinguish it from artificial sources.
Measuring Circadian Light: From Lux to Circadian Stimulus
Traditional light measurement in lux is designed to match human visual sensitivity but fails to capture circadian effectiveness. Researchers have developed specialized metrics to quantify circadian light exposure:
| Metric | Description | Range |
|---|---|---|
| CL (Circadian Light) | Irradiance weighted by circadian spectral sensitivity | 0 to unlimited (photopic lux equivalent) |
| CLA (Circadian Light from Above) | CL from light sources above the horizontal plane at the eye | 0 to unlimited |
| CS (Circadian Stimulus) | Predicted melatonin suppression on a scale | 0 to 0.7 (0% to 75% suppression) |
These models, particularly the Rea et al. phototransduction model, account for the complex interactions between melanopsin, cones, and rods to predict how effectively a given light exposure will regulate the circadian system.
How Circadian Light Influences Melatonin and Sleep
The pineal gland produces melatonin, often called the “hormone of darkness,” which rises in the evening to promote sleep and falls during the day to support wakefulness. Light is the most powerful regulator of this melatonin rhythm, and understanding this relationship is key to optimizing sleep health.
The Power of Blue Light on Melatonin Suppression
Not all wavelengths of light are equally effective at suppressing melatonin. Research consistently shows that blue light (approximately 460-480 nm) has the strongest suppressive effect, corresponding to melanopsin’s peak sensitivity. Studies have documented that saturating circadian light exposure can suppress melatonin by up to 75%.
This wavelength-dependent response explains why evening exposure to blue-enriched light from screens, LED bulbs, and electronic devices can delay sleep onset and reduce sleep quality. Conversely, amber or red-shifted lighting in the evening preserves melatonin production and supports natural sleep preparation.
Timing Matters: The Phase Response Curve
The circadian system doesn’t just respond to whether light is present—it also interprets when light exposure occurs. This relationship is described by the phase response curve:
- Morning light exposure: Advances the circadian phase, making you feel alert earlier and promoting earlier sleep onset
- Evening/night light exposure: Delays the circadian phase, pushing back sleep timing and potentially causing later wake times
- Afternoon light: Has minimal phase-shifting effects but contributes to overall circadian strength
Screen Time and Sleep Disruption
Research shows that smartphone night shift modes can reduce melanopsin activation by up to 67% at full brightness. However, even with these filters, prolonged screen use before bed can still disrupt sleep through both light exposure and cognitive stimulation. For best results, limit screen time at least 1-2 hours before bed.
Real-World Impact on Sleep Quality and Duration
Clinical studies have demonstrated measurable improvements in sleep outcomes when circadian light exposure is optimized. A comprehensive review found that appropriate circadian lighting interventions can:
- Reduce sleep onset latency (time to fall asleep)
- Increase total sleep duration
- Improve sleep consolidation and reduce nighttime awakenings
- Enhance subjective sleep quality ratings
- Support treatment of circadian rhythm sleep disorders
These benefits extend beyond simple sleep metrics, with properly timed light exposure also improving daytime alertness, mood, and cognitive performance.
Measuring Circadian Light: Technologies and Protocols
Translating circadian light science into practical applications requires accurate measurement tools and standardized protocols. Over the past decade, several technologies have emerged to quantify personal circadian light exposure and guide lighting design.
The Daysimeter: Personal Circadian Light Monitoring
The Daysimeter is a wearable device developed by researchers at the Lighting Research Center that measures circadian light exposure in real-world settings. Unlike standard light meters calibrated for visual sensitivity, the Daysimeter:
- Weighs spectral power distributions according to circadian sensitivity
- Accounts for light direction and angle of incidence
- Calculates circadian stimulus (CS) and circadian light (CL) metrics
- Records continuous exposure patterns over 24-hour periods
This device has been instrumental in research studies documenting how occupational, residential, and seasonal factors affect circadian light exposure, revealing that many people receive insufficient daytime circadian stimulation while experiencing excessive nighttime exposure.
The UC Davis Circadian Protocol
One of the most comprehensive practical applications of circadian light science is the UC Davis Circadian Protocol, developed by the California Lighting Technology Center. This evidence-based lighting system aims to support circadian health by:
- Maximizing melanopic light during daytime: Using blue-enriched white light (5000-6500K) to provide strong circadian stimulation and promote alertness
- Minimizing melanopic light in evening: Transitioning to warm amber tones (1800-2700K) that preserve melatonin production
- Supporting nighttime navigation: Providing low-level, amber lighting for safety without circadian disruption
- Mimicking natural light cycles: Gradually transitioning color temperature and intensity throughout the day
The protocol has been implemented in various settings, including the UC Davis Honda Smart Home, where it has demonstrated practical feasibility for residential applications. Initial findings suggest improvements in sleep quality, mood, and safety for residents.
Challenges in Standardizing Circadian Light Measurement
Despite significant progress, several challenges remain in establishing universal circadian light standards:
- Individual variability: Age, genetics, and prior light history affect circadian sensitivity
- Complex environments: Real-world settings involve multiple light sources with varying spectral characteristics and geometries
- Competing models: Different research groups have proposed alternative circadian phototransduction models with varying predictions
- Practical implementation: Translating laboratory findings to cost-effective, user-friendly lighting products remains challenging
Ongoing research aims to refine measurement approaches and establish consensus standards that can guide lighting design and public health recommendations.
Practical Applications of Circadian Lighting in Homes and Workplaces
Understanding circadian light science is valuable only when translated into practical strategies for optimizing daily light exposure. Here are evidence-based approaches for different settings.
Home Lighting Strategies
Creating a circadian-friendly home environment doesn’t require expensive renovations. Focus on these key principles:2
- Morning bright light exposure: Open curtains immediately upon waking, or use bright (5000+ lux) blue-enriched light for 30-60 minutes in spaces where you spend morning time
- Daytime natural light maximization: Position workspaces near windows, use light-colored walls to reflect daylight, and spend time outdoors when possible
- Evening amber transition: Switch to warm-toned bulbs (2000-2700K) 2-3 hours before bedtime in living spaces and bedrooms
- Nighttime amber navigation lighting: Use motion-activated amber night lights (avoiding blue/white LEDs) for bathroom and hallway safety
- Bedroom darkness: Use blackout curtains and eliminate blue LED indicator lights from electronics
Practical Product Choices
Several manufacturers now offer circadian-friendly lighting solutions, including tunable LED bulbs that automatically adjust color temperature throughout the day, sunrise simulation alarm clocks for gentle morning awakening, and amber-filtered bulbs for evening use. When selecting products, look for specifications that include melanopic lux or circadian stimulus values, not just traditional lux measurements.
Workplace Lighting Interventions
Office environments often provide inadequate daytime circadian stimulation (typically 200-500 lux) compared to outdoor daylight (10,000-100,000 lux). Workplace interventions can include:
- Installing high-intensity blue-enriched lighting at workstations (minimum 1000 melanopic lux recommended)
- Encouraging outdoor breaks during lunch or mid-afternoon
- Using personal light therapy devices for desk workers with limited window access
- Implementing dynamic lighting systems that adjust throughout the workday
Healthcare Settings: Improving Patient Outcomes
Hospitals and care facilities increasingly recognize circadian lighting’s role in patient recovery. Research shows that circadian-optimized lighting in healthcare environments can:
- Reduce delirium in intensive care patients
- Decrease fall rates among elderly residents
- Improve mood and reduce agitation in dementia patients
- Accelerate recovery and reduce length of hospital stays
- Support staff alertness during night shifts
UC Davis research found that amber lighting significantly reduces stress recovery time in clinical environments, suggesting potential applications in emergency departments and surgical recovery areas.
Shift Work: Mitigating Circadian Disruption
Shift workers face unique challenges as their work schedules conflict with natural circadian rhythms. The CDC and NIOSH have studied targeted lighting interventions for this population:
- Red light glasses during night shifts: Allow visual function while minimizing melatonin suppression, supporting alertness without preventing post-shift sleep
- Bright blue-enriched light during work hours: Can help synchronize circadian rhythms to night schedules when consistently applied
- Blue-blocking glasses before bedtime: Protect melatonin production when traveling home in morning daylight
- Scheduled light exposure protocols: Strategically timed bright light can help shift workers adapt more quickly to changing schedules
| Setting | Daytime Strategy | Evening Strategy | Key Benefits |
|---|---|---|---|
| Home | Natural light + bright white LEDs | Warm amber lighting (1800-2700K) | Better sleep quality, natural wake times |
| Office | High-intensity blue-enriched task lights | N/A (reduce evening overtime) | Enhanced alertness, productivity |
| Healthcare | Dynamic lighting mimicking daylight | Warm, dimmed lighting | Faster recovery, reduced falls |
| Shift Work | Bright blue light during work | Red/amber light, blue blockers | Improved adaptation, sleep quality |
Energy Efficiency Considerations
A common concern about circadian lighting is energy consumption. However, modern LED technology makes it possible to provide adequate circadian stimulation while maintaining energy efficiency. Strategies include:
- Using task lighting to deliver high circadian stimulus at specific locations rather than illuminating entire spaces
- Implementing occupancy sensors and daylight harvesting to reduce unnecessary artificial lighting
- Selecting LED fixtures with high melanopic/photopic ratios to maximize circadian effect per watt
- Timing high-intensity circadian lighting to periods when it provides greatest benefit (morning and early afternoon)
Circadian Light and Health: Benefits and Risks
The relationship between circadian light exposure and health extends far beyond sleep. Research over the past two decades has revealed connections between circadian disruption and a wide range of health outcomes.
Health Risks of Circadian Disruption
Chronic circadian misalignment—whether from shift work, excessive nighttime light exposure, or insufficient daytime light—has been linked to:
- Metabolic disorders: Increased risk of obesity, type 2 diabetes, and metabolic syndrome
- Cardiovascular disease: Higher rates of hypertension, heart attack, and stroke
- Cancer: Elevated risk of breast, prostate, and colorectal cancers (shift work classified as “probably carcinogenic” by IARC)
- Mood disorders: Greater susceptibility to depression, anxiety, and seasonal affective disorder
- Cognitive decline: Accelerated cognitive aging and increased dementia risk
- Immune dysfunction: Impaired immune response and increased inflammation
These associations appear to be mediated through multiple mechanisms, including disrupted melatonin rhythms, altered clock gene expression, hormonal imbalances, and inflammatory processes.
Shift Workers at Greatest Risk
Epidemiological studies show that long-term shift workers have significantly elevated health risks. The CDC reports that shift workers experience higher rates of metabolic disorders and cancer linked to circadian disruption. Even short-term circadian misalignment can impair glucose metabolism and increase appetite for unhealthy foods within days.
Benefits of Optimized Circadian Lighting
Conversely, maintaining robust circadian rhythms through appropriate light exposure offers substantial health benefits:
- Improved sleep: Faster sleep onset, longer duration, better consolidation, and enhanced sleep quality
- Enhanced mood: Reduced depression and anxiety symptoms, particularly for seasonal affective disorder
- Better cognitive function: Improved attention, memory, reaction time, and decision-making
- Metabolic health: Better glucose regulation, appetite control, and weight management
- Stronger immune function: Enhanced immune surveillance and reduced inflammatory markers
- Cardiovascular protection: Lower blood pressure and reduced cardiovascular disease risk
Light Therapy for Mood and Cognitive Enhancement
Beyond preventing circadian disruption, targeted light therapy can actively treat certain conditions. Bright light therapy (typically 10,000 lux for 30 minutes daily) is an established treatment for:
- Seasonal affective disorder (SAD) with efficacy comparable to antidepressant medications
- Non-seasonal depression as an adjunct to other treatments
- Sleep phase disorders (delayed and advanced sleep phase syndrome)
- Jet lag and shift work adjustment
Research also suggests potential cognitive benefits from optimized daytime light exposure in aging populations, with some studies showing improved cognitive performance and reduced progression of cognitive decline.
Managing Blue Light Exposure from Screens and LEDs
Modern environments expose us to blue-enriched LED lighting and electronic screens far more than previous generations experienced. While blue light during daytime is beneficial for circadian entrainment, excessive evening exposure can be problematic. Evidence-based management strategies include:
- Using device “night mode” settings that reduce blue light emission in the evening (though these should be considered partial solutions, not complete fixes)
- Installing software like f.lux that automatically adjusts screen color temperature based on time of day
- Wearing blue-blocking glasses (amber-tinted) in the 2-3 hours before bedtime if screen use is unavoidable
- Maintaining distance from screens to reduce light intensity at the eye
- Prioritizing behavioral changes (reducing evening screen time) over technological filters when possible
Blue Light Is Not the Enemy
Popular media often portrays blue light as universally harmful, but this oversimplifies the science. Blue light is essential for circadian health when received at appropriate times. The problem is not blue light itself, but rather its timing—beneficial during the day, disruptive at night. Focus on optimizing the timing of blue light exposure rather than eliminating it entirely.
Future Directions in Circadian Lighting Research
- Personalized circadian lighting: Developing algorithms that account for individual differences in circadian sensitivity, chronotype, and light history
- Spectral optimization: Engineering light sources with spectral compositions that maximize circadian effectiveness while minimizing energy consumption and visual discomfort
- Wearable integration: Incorporating circadian light monitoring and feedback into smartwatches and fitness trackers
- Architectural applications: Designing buildings with circadian-optimized daylighting and artificial lighting systems from the ground up
- Therapeutic applications: Exploring circadian lighting for conditions including Alzheimer’s disease, ADHD, and autism spectrum disorders
- Color vision circuits: Further investigating how retinal color processing contributes to circadian and mood regulation beyond simple melanopsin activation
As research progresses and technologies mature, circadian lighting is poised to become a standard consideration in public health, architecture, workplace design, and personal wellness.
Frequently Asked Questions About Circadian Light
Circadian light refers to the specific characteristics of optical radiation that influence the human circadian system—our internal 24-hour biological clock. Unlike “regular” or visual light, which enables us to see through rod and cone photoreceptors, circadian light is detected primarily by specialized retinal ganglion cells containing melanopsin. These cells send signals to the brain’s circadian control center (suprachiasmatic nucleus) rather than to visual processing areas. The key difference is that circadian light is weighted toward blue wavelengths (~480 nm) and is measured using different metrics (circadian stimulus, melanopic lux) than visual light (photopic lux).
Circadian light, particularly blue wavelengths, powerfully suppresses the production of melatonin—the hormone that promotes sleep. When blue-enriched light hits melanopsin-containing cells in your retina, it signals the brain that it’s daytime, inhibiting melatonin release from the pineal gland. This suppression can reach up to 75% with saturating light exposure. Consequently, bright blue light during the day helps maintain alertness and consolidates nighttime sleep, while blue light in the evening delays melatonin onset, making it harder to fall asleep and reducing sleep quality. Conversely, warm amber light in the evening allows melatonin to rise naturally, facilitating sleep onset.
Yes, targeted circadian lighting interventions show promise for mitigating some health impacts of shift work. Research by the CDC and NIOSH has demonstrated that bright blue-enriched light during night shifts can help synchronize circadian rhythms to work schedules, improving alertness and performance. Interestingly, red light glasses during night shifts have been shown to improve alertness without suppressing melatonin, potentially allowing for better sleep after shifts end. However, it’s important to note that lighting interventions can only partially compensate for the inherent circadian disruption of shift work—behavioral strategies and schedule design are also crucial.
The UC Davis Circadian Protocol provides evidence-based guidance for home circadian lighting. Best practices include: maximizing bright, blue-enriched light exposure in the morning and throughout the day (ideally from natural daylight, supplemented with bright white LEDs if needed); transitioning to warm amber-toned lighting (1800-2700K) 2-3 hours before bedtime; using low-level amber navigation lights for nighttime safety; maintaining bedroom darkness during sleep; and avoiding bright screens in the evening. The goal is to mimic natural light cycles—bright and blue during the day, dim and amber in the evening, dark at night.
Circadian light is measured using specialized metrics and devices that account for the spectral sensitivity of the circadian system, which differs from visual sensitivity. Key metrics include Circadian Light (CL), which weights irradiance according to circadian spectral sensitivity; Circadian Light from Above (CLA), which specifically measures light from overhead sources; and Circadian Stimulus (CS), which predicts the degree of melatonin suppression on a scale from 0 to 0.7. Devices like the Daysimeter are calibrated to these circadian metrics and can track personal exposure patterns over 24-hour periods, providing much more relevant data for circadian health than traditional light meters measuring photopic lux.
Yes, blue light from screens can disrupt circadian rhythms when exposure occurs in the evening or at night. Electronic devices like smartphones, tablets, and computers emit significant amounts of blue wavelengths that activate melanopsin and suppress melatonin production. However, the magnitude of disruption depends on brightness, duration, and timing. Screen use in the evening delays sleep onset and can reduce sleep quality. “Night shift” modes that reduce blue light emission can decrease melanopsin activation by up to 67%, but this is only a partial solution—behavioral changes like limiting screen time 1-2 hours before bed are more effective. It’s also worth noting that daytime screen exposure is not problematic and may even contribute beneficially to circadian entrainment.
The UC Davis Circadian Protocol is an evidence-based lighting system developed by the California Lighting Technology Center to support circadian health through optimized light exposure patterns. The protocol involves maximizing melanopic light exposure during daytime hours using blue-enriched white light (5000-6500K), then transitioning to warm amber lighting (1800-2700K) in the evening to minimize melanopic stimulation and preserve melatonin production. For nighttime navigation, it recommends low-level amber lighting that provides safety without circadian disruption. The system is designed to mimic natural daylight cycles and has been implemented in settings like the UC Davis Honda Smart Home, demonstrating practical applications for residential and healthcare environments.
Yes, chronic circadian disruption is associated with numerous serious health risks. Research has linked circadian misalignment to increased rates of metabolic disorders (obesity, type 2 diabetes, metabolic syndrome), cardiovascular disease, certain cancers (breast, prostate, colorectal), mood disorders (depression, anxiety), cognitive decline, and immune dysfunction. Shift workers, who experience the most severe circadian disruption, face particularly elevated health risks. The International Agency for Research on Cancer has classified shift work involving circadian disruption as “probably carcinogenic to humans.” These health impacts appear to be mediated through disrupted melatonin rhythms, altered clock gene expression, hormonal imbalances, and increased inflammation.
Emerging research suggests that circadian lighting may help reduce stress and improve stress recovery. UC Davis research has found that amber lighting significantly reduces stress recovery time in clinical environments, suggesting potential applications in medical settings where patients and staff experience high stress levels. More broadly, optimized circadian light exposure supports overall circadian rhythm stability, which is associated with better emotional regulation, reduced anxiety, and improved mood. While circadian lighting alone cannot eliminate stress, it appears to be one component of creating environments that support psychological well-being and resilience.
The retina processes circadian light through a complex network involving multiple cell types. Specialized intrinsically photosensitive retinal ganglion cells (ipRGCs) containing melanopsin are the primary circadian photoreceptors. However, recent research from the University of Washington has revealed that ipRGCs also receive input from cone photoreceptors via specialized amacrine cells, creating a color-opponent circuit that compares signals between different wavelengths. This allows the circadian system to detect not just brightness but also the color composition of light, helping distinguish natural daylight from artificial sources. At low light levels, rods also contribute input to ipRGCs. These integrated signals travel via the optic nerve to the suprachiasmatic nucleus in the brain’s hypothalamus, which serves as the master circadian pacemaker, and to other brain regions involved in mood, alertness, and other non-visual responses to light.
Conclusion: Harnessing Circadian Light for Better Health
The discovery that light serves dual functions—enabling vision and regulating circadian rhythms—represents one of the most important insights in chronobiology and lighting science. Understanding circadian light empowers us to make informed decisions about our light environment, with profound implications for sleep quality, mental health, cognitive performance, and long-term disease risk.
The key principles are straightforward: seek bright, blue-enriched light during daytime hours, transition to warm amber tones in the evening, and maintain darkness at night. While these recommendations align with natural light cycles humans evolved with, modern lifestyles often work against them—indoor jobs, artificial lighting, and evening screen use create circadian disruption that our ancestors never experienced.
Fortunately, practical solutions are increasingly accessible. Whether through simple behavioral changes (morning outdoor walks, dimming evening lights), inexpensive products (amber bulbs, blue-blocking glasses), or comprehensive systems (UC Davis Circadian Protocol, dynamic workplace lighting), opportunities exist at every level to optimize circadian light exposure.
As research continues to refine our understanding and technology evolves to implement circadian principles more seamlessly, circadian lighting will likely become standard in homes, workplaces, and healthcare settings—just as ergonomic furniture and air quality considerations have become recognized elements of healthy built environments.
Take Action Today
Start optimizing your circadian light exposure with these simple steps: Get outdoors within an hour of waking for at least 10-15 minutes. Install warm amber bulbs (2000-2700K) in your bedroom and evening living spaces. Enable night shift mode on all devices and consider blue-blocking glasses for evening screen use. Maximize natural light in your workspace, or add a bright desk lamp for morning hours. These small changes can yield measurable improvements in sleep, mood, and energy within days to weeks.
The science of circadian light reminds us that our biology remains deeply connected to natural light cycles. By respecting these ancient rhythms while leveraging modern technology thoughtfully, we can create environments that support rather than undermine our health and well-being.
References
- Rea MS, Figueiro MG, Bullough JD, Bierman A. A model of phototransduction by the human circadian system. Journal of Circadian Rhythms. 2010. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC2851666/
- UC Davis Wellness. How to Harness the Power of Light to Support Your Circadian Rhythm. 2024. Available at: https://wellness.ucdavis.edu/videos/how-to-harness-the-power-of-light-to-support-your-circadian-rhythm/
- Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV. The inner clock—Blue light sets the human rhythm. Journal of Biophotonics. 2019. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC6751071/
- NIOSH Science Blog. Lighting the Way: Perspectives on the Health of Shift Workers. Centers for Disease Control and Prevention. 2020. Available at: https://blogs.cdc.gov/niosh-science-blog/2020/12/18/lighting-shift-work/
- UW Medicine Newsroom. Let there be circadian light. 2020. Available at: https://newsroom.uw.edu/news-releases/let-there-be-circadian-light
- National Institute of General Medical Sciences. Circadian Rhythms Fact
Disclaimer:
The information provided on MD-Pilot is for educational and informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Weekly Health Intel
Get evidence-based health tips, latest research, and exclusive guides delivered weekly