night sky

CIRCADIAN® announced today that it has acquired controlling stake in ZircLight™ Inc., which holds the core intellectual property rights to LED lighting systems, eyewear and computer screen devices designed to alleviate the negative effects of artificial lighting in our nighttime environments.

The technological developments of CIRCADIAN ZircLight build upon a growing body of research showing that exposure to light at night causes a disruption of brain neuroendocrine systems, including melatonin and cortisol rhythms. This research suggests that the myriad of health issues related to shift workers may be due to the nighttime light exposure during night shifts.

Health Effects of Light Exposure at Night

Mounting medical evidence led the World Health Organization to conclude in December 2007 that light exposure in night shift work is “probably carcinogenic to humans”. Two years later in 2009, BBC News reported that the Danish government has begun paying compensation to women who have developed breast cancer after long spells working nights.

It was long thought that the harmful effects of shift work were caused by sleep deprivation. However, we now know that much of the adverse effect is actually related to circadian timing disruption caused by nocturnal light exposure.

The hormonal dysregulation found with nighttime light exposure is associated with fatigue, loss of alertness, vigilance errors and reduced performance in night shift employees. Night shift light exposure also disrupts genetic disease markers and substantial evidence is building for increased health risks such as heart disease, diabetes, sleep disorders, and breast, prostate and colon cancers in night shift workers regularly exposed to light at night. There is therefore a substantial dark side to the use of electric light at night.

Discovering the Culprit: Blue Wavelength Light

Recent research shows that the harmful effects of light at night are largely mediated by certain blue wavelengths which are detected by newly-discovered visual pathway that is especially sensitive to blue light.

Blue light during the day is critical to synchronizing our circadian rhythms, but we are not designed to see blue light at night. Many of the adverse effects of chronic light exposure at night appear to be mediated by abnormal nighttime stimulation of this time-keeping pathway by the blue light wavelengths in the light spectrum. When this pathway is disrupted by exposure to white light or only blue light at night, it initiates a chain reaction that results in decreased energy, mood, performance and vigilance and increased risk of errors, accidents, injuries, absenteeism and workplace turnover.

Over the long- term, continuous light exposure at night may result in sustained hormonal dysregulation leading to significant health consequences including sleep disorders, diabetes, heart disease, depression and even certain types of cancer (e.g., breast, prostate and colon cancers).


CIRCADIAN Light is developing spectrum-specific circadian-modulated ZircLight LED lighting, filtered eyewear and display screens to provide a highly effective solution to nocturnal workplace lighting that directly based on the mechanisms underlying the light-induced dysfunction. Working with partners who are leaders in LED lighting and light sensors and controls, we are bringing a healthy revolution to how light is used at night.

Extensive peer-reviewed published work in animals and humans by Dr. Robert Casper and his team at the University of Toronto, protected by issued worldwide patents owned by CIRCADIAN ZircLight, showed that filtering out specific wavelengths of blue light prevents many of the adverse health, safety and performance effects of night shift work.

CIRCADIAN Press Release

Learn more about CIRCADIAN’s acquisition of ZircLight™ by reading CIRCADIAN’s latest press release. Want to learn more about the science behind ZircLight™? Click here to learn more about ZircLight technology.

CIRCADIAN is pleased to announce the launch of our newest service, our Corporate Sleep Programs!

Why Corporate Sleep Programs?

In our 24/7 culture, sleep is being challenged. Research continues to add to the clear evidence that sleep deprivation directly impacts nearly every cognitive and physiological function that is imperative for optimal employee performance. As the demands on the global workforce increasingly stretch the boundaries of employee work hours, there is a need to provide sleep solutions for ALL corporate employees, including those who traditionally were thought to work “normal” hours.

Why is employee sleep behavior a corporate management issue? Because sleep directly impacts work performance.  Research confirms that sleep impacts performance, productivity, absenteeism, turnover rates, profitability, safety, health and health care costs, for both employers and their employees.  Furthermore, life outside of the workplace may also be impacted by sleep deprivation or poor sleep quality, leading to strains on functionality and well-being both at home and at work.

Sleep is a risk management issue, requiring the attention of corporate management in order to optimize its workforce.

What does CIRCADIAN's Corporate Sleep Programs include?

CIRCADIAN’s Corporate Sleep Programs offer corporations customized and research-based solutions to address the issue of Sleep Wellness for all levels of a corporation or organization’s workforce. The CIRCADIAN Corporate Sleep Programs includes:

Assessment of corporate goals and strategic needs

  • Determine client timetable, budget and outcome goals
  • Customize program scope to serve management goals
  • Design in-person, virtual  and/or Train-the-Trainer programming

Pathway to sleep improvement

  • Keynote presentations
    • Engage both management and employees with compelling sleep research and issues relevant to the audience.
    • Aim at heightening awareness to key issues and developing basic sleep knowledge.
  • Sleep Improvement Programming
    • Create seminars and training that focus on building an understanding of sleep basics, self-assessment and sleep improvement strategies, leading to effective and sustainable change. 
    • Implement strategic initiatives and tools
      • Foster a team-centric approach
      • Empower people to make lasting changes to optimize their sleep quality and quantity.
      • Provide participants with a forum for feedback

Research, metrics and data

  • Design analytical approaches to fit client’s needs
  • Incorporate program assessment and modifications based on management and participant feedback
  • Complete documentation/research regarding program metrics and data per client request

Corporate Sleep Director, Nancy H. Rothstein  

CIRCADIAN has joined forces with Nancy H. Rothstein, MBA, The Sleep Ambassador® to address the issues of sleep deficit and fatigue seen in employees of all levels within organizations and in the workplace. The combined expertise of both CIRCADIAN and Nancy provides organizations with invaluable, unique insights and specialized solutions for these issues. 

About Nancy...

sleep ambassador and nancy picAs Director of CIRCADIAN’s Corporate Sleep Programs, Nancy H. Rothstein, MBA, The Sleep Ambassador®, is a leader in bringing Sleep Wellness to the corporate sector. Nancy has consulted and lectured on Sleep Wellness to Fortune 500 corporations, the travel industry, universities/schools and to organizations, reflecting her dedication to educating and raising awareness about the importance of sleep to live and work at your best. With decades of experience in the financial and corporate sectors, Nancy brings a broad understanding of how sleep impacts corporate workforce performance and the bottom line.

  • Nancy serves as a member of the Board of the American Sleep Apnea Association and the American Academy of Physiological Medicine and Dentistry.
  • Nancy serves as an Adjunct Faculty member at NYU where she developed and teaches an online course on Sleep Wellness.
  • Inspired by personal experience, Nancy authored My Daddy Snores, a children’s book published by Scholastic Inc. which has sold over 400,000 copies to date. She created a family-friendly website (, offering viewers comprehensive resources about snoring, sleep apnea and sleep in general.
  • Want to learn more about Nancy? Visit for more information.
Want to learn more about the Corporate Sleep Programs?
Click here to contact CIRCADIAN for more information about the Corporate Sleep Programs

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