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The Power of Light: How it Influences Your Nervous System, Circadian Clock, and Sleep

Updated: Oct 18, 2023


Light is a fundamental aspect of our daily lives, shaping our environment and affecting our well-being in profound ways. From the glow of the morning sun to the soft dimness of twilight, light plays a pivotal role in regulating our nervous system, circadian clock, and ultimately, our sleep quality. In this blog post, we'll explore the intricate relationship between light and these essential aspects of our health, backed by scientific references.

Light and the Nervous System

The nervous system is the body's intricate communication network, responsible for transmitting signals between the brain and various parts of the body. Light has a significant impact on the nervous system, both positively and negatively.

Positive Effects:

a. Mood Enhancement: Exposure to natural daylight, particularly in the morning, can boost serotonin levels in the brain, enhancing mood and promoting a sense of well-being.

b. Increased Alertness: Bright light, such as sunlight or specific artificial lighting, can improve alertness, cognitive function, and concentration.

Negative Effects:

a. Stress and Anxiety: Overexposure to artificial blue light, especially in the evening, can disrupt the nervous system by increasing stress hormones like cortisol, leading to alertness at the wrong time, restlessness, and potentially anxiety.

b. Disrupted Melatonin Production: Excessive artificial light exposure at night can suppress melatonin production, making it difficult to activate the parasympathetic nervous system and relax.

Light and the Circadian Clock

Our circadian rhythm is an internal biological clock that regulates the timing of various physiological processes, including sleep-wake cycles, body temperature, metabolism, and hormone production. In 2017, Jeffrey C. Hall et al. were even awarded the Nobel Prize in Medicine for discovering that light is the most potent external factor that influences our circadian clock.

Positive Effects:

a. Synchronization: Exposure to natural light during the day helps to align our circadian rhythms with the 24-hour day-night cycle, leading to improved sleep and overall health.

b. Alertness and Performance: A well-synchronized circadian clock can enhance alertness and cognitive performance during the daytime.

Negative Effects:

a. Circadian Disruption: Irregular light exposure, particularly from artificial sources at night, can disrupt the circadian rhythm, contributing to sleep disorders, mood disturbances, and health issues.

b. Shift Work Problems: Individuals working night shifts or irregular hours often experience circadian misalignment, which can lead to sleep disturbances and health problems.

Light and Sleep

Sleep is crucial for our physical and mental well-being. Light, or lack thereof, plays a pivotal role in our ability to fall asleep and enjoy restorative slumber.

Positive Effects:

a. Regulated Sleep-Wake Cycles: Exposure to natural light during the day and darkness at night helps regulate our sleep-wake cycles, promoting healthier sleep patterns.

b. Improved Sleep Quality: A well-established circadian rhythm contributes to deeper and more restful sleep.

Negative Effects:

a. Insomnia: Exposure to artificial light, especially blue light from screens, before bedtime can interfere with the production of melatonin, making it harder to fall asleep and stay asleep.

b. Delayed Sleep Phase: Irregular light exposure, such as late-night screen use, can lead to a delayed sleep phase, making it challenging to wake up early and maintain a consistent sleep schedule


Erling Haaland's Secret to Optimal Sleep

World-renowned Manchester City striker Erling Haaland, known for his exceptional skills on the field, attributes part of his success to Ra Optics sunset lenses. Haaland uses these specialized lenses three hours before bedtime to optimize his sleep, calm his nervous system, and support a healthy circadian rhythm. By reducing his exposure to disruptive artificial light, Haaland ensures he gets the rest he needs to perform at his best. Luckily, anyone benefits from this intervention, not just top athletes.

How Ra Optics Helps

In the pursuit of harnessing the positive effects of light while mitigating its potentially detrimental impacts on the nervous system, circadian clock, and sleep, Ra Optics offers a game-changing solution: blue light protection glasses. These specially designed glasses are engineered to filter out the harmful blue light emitted by digital screens and artificial lighting sources, which can disrupt circadian rhythms and hinder melatonin production. By wearing Ra Optics blue light protection glasses, you can create a shield against the disruptive effects of excessive blue light exposure, ensuring that your circadian rhythm stays on track, your nervous system remains balanced, and your sleep quality is optimized. Whether you're a professional athlete like Erling Haaland or an individual seeking to enhance your overall well-being, Ra Optics provides a tool to help you thrive in today's digitally illuminated world.

Make sure to use code MVMT at checkout!


The influence of light on our nervous system, circadian clock, and sleep is undeniable. Understanding how light affects these crucial aspects of our health can empower us to make informed choices about our exposure to light throughout the day.


  • Cajochen, C., & Dijk, D. J. (2003). Melatonin and the circadian regulation of sleep–wake timing: physiological and clinical perspectives. Behavioral Brain Research, 125(1-2), 57-74.Vandewalle, G., Schwartz, S., Grandjean, D., Wuillaume, C., Balteau, E., Degueldre, C., ... & Maquet, P. (2010). Spectral quality of light modulates emotional brain responses in humans. Proceedings of the National Academy of Sciences, 107(45), 19549-19554.

  • 2017 Nobel Prize in Physiology or Medicine, Jeffrey C. Hall, Michael Rosbash and Michael W. Young

  • Roenneberg, T., & Merrow, M. (2007). Entrainment of the human circadian clock. Cold Spring Harbor Symposia on Quantitative Biology, 72, 293-299.

  • Wright, K. P., & Czeisler, C. A. (2002). Absence of circadian phase resetting in response to bright light behind the knees. Science, 297(5581), 571-573.

  • Brainard, G. C., Hanifin, J. P., Greeson, J. M., Byrne, B., Glickman, G., Gerner, E., & Rollag, M. D. (2001). Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. Journal of Neuroscience, 21(16), 6405-6412.

  • Khalsa, S. B., Jewett, M. E., Cajochen, C., & Czeisler, C. A. (2003). A phase response curve to single bright light pulses in human subjects. Journal of Physiology, 549(3), 945-952.

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