BioClock contributes to international consensus statement on light and health
Friday, May 16 marks UNESCO’s International Day of Light. On this day, BioClock and international partners draw attention to the importance of responsible light use for the health of people and nature.
BioClock researchers were closely involved in the development of 26 international consensus statements, created as part of the Light for Public Health Initiative. This campaign was set up by a consortium of 21 leading experts in chronobiology, neuroscience, lighting science, and public health from Europe, North America, Asia, and Australia.
The statements are the result of two structured rounds of expert review (Delphi process) and provide globally evidence-based information on how light exposure through the eyes affects the biological clock, sleep, mood, and cognitive functioning.
Key messages:
The Light for Public Health Initiative aims to inspire health organizations, designers, policymakers, and citizens worldwide to use light more consciously. More information and the full list of statements can be found at: https://lightforpublichealth.org/consensus-statements.html
BioClock is proud to be a supporter of this international initiative.
Frequently Asked Questions (FAQ)
What is the Light for Public Health initiative?
A global communication campaign created by scientists to raise awareness of how light through the eyes affects health and well-being.
Who is behind the initiative?
It is led by an international working group of experts and supported by five core organizations: the International Commission on Illumination (CIE), the Society for Light, Rhythms and Circadian Health (SLRCH), the Daylight Academy (DLA), the Good Light Group (GLG), and the Center for Environmental Therapeutics (CET).
Why now?
Most people spend most of their time indoors, often receiving suboptimal light. Addressing this is essential for public health. By improving access to healthy lighting environments, we can support both mental and physical well-being at a population level.
What are the health effects of light exposure?
Light affects health by regulating mood, alertness, and sleep. Daylight enhances well-being, while evening light can delay sleep. Inadequate light disrupts daily circadian rhythms and sleep and contributes to various health problems.
Who is the initiative for?
Everyone! The general public, parents, patients, health and safety professionals, designers, and architects.
How was scientific consensus established?
Consensus was reached through a modified Delphi process, which involved:
- Two structured rounds of expert review and anonymous rating
- A predefined agreement threshold of ≥75% for consensus
- Revisions based on feedback from scientists and communication experts
- Final readability testing to ensure accessibility
This approach ensured that the final messages are both scientifically accurate and understandable by a broad audience.
Who were the experts who wrote this?
The consensus process was led by a coordinating committee of six scientists from five major organizations (CIE, SLRCH, DLA, GLG, CET), supported by a broader international consortium of 21 experts. The experts represent fields such as chronobiology, neuroscience, psychology, lighting science, and public health, and are affiliated with institutions in Europe, North America, Asia, and Australia. The full list can be found at lightforpublichealth.org.
Who funded this initiative?
The initial expert meeting took place as part of the Ladenburg Roundtable, which was supported by the Daimler and Benz Foundation. The funders played no role in the design, conduct, or reporting of this work. Additional support is provided by the supporting organisations.
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The BioClock Consortium is funded by the NWA-ORC programme of the Dutch Research Council (NWO; project number 1292.19.077).