Search Results

Launch of Good Light Group Asia We are very pleased that Lawrence and his team have taken the initiative to establish Good Light Group Asia. This organization is dedicated to promoting the use of good indoor light. Across Asia, we see a growing awareness of the impact that light and lighting have on health and well-being. This awareness can be seen within the lighting industry, academic institutions, and governments. This is highly relevant. Just like elsewhere in the world, most people in Asia spend their days indoors, often shielded from daylight. They are exposed to light levels that are too low during the daytime and too bright in the evening. Many of us recognize the loss of energy this causes in our daily lives. Scientific evidence clearly shows that these lighting patterns affect sleep quality, mood, alertness, energy levels, and overall health. We strongly believe that Asia has a unique opportunity to take these findings seriously. The region can become the global leader in developing healthier lighting practices and innovative lighting solutions. Asia is home to an exceptionally innovative lighting industry. This industry is strongly supported by universities, research institutes, and standards organizations. With more than half of the world’s lighting manufacturers located in Asia, the potential for positive impact is enormous. Good Light Group Asia will play an important role in translating scientific knowledge into clear and practical guidelines for the lighting value chain. This includes lighting manufacturers, lighting designers, architects, installers, and, last but not least, the general public. By increasing public awareness and stimulating innovation, we can meaningfully improve the quality of life for billions of people. We are proud and personally very excited that we are now in the process of creating Good Light Group Asia as an independent non-profit organization. It will be closely aligned with the global mission, values, and recommendations of the Good Light Group. We look forward to working together with our partners in Asia to improve health and well-being through better light. Jan Denneman Chair of the Board

SunLED is a Dutch start-up at the forefront of near-infrared light research and its effects on human health and well-being. The near-infrared part of the sunlight spectrum is often missing from our indoor lives; however, it is essential for our bodies. Near-infrared light can penetrate deep into our skin and activate energy production in our cells. It has multiple proven health benefits for the human body, including:  Improved mental health - makes you feel more energized, focused, and improves your mood  A better immune system reduces inflammation and helps balance your immune system.  Improved physical health – lowers resting heart rate, supporting heart function. ...and more. SunLED develops near-infrared light technologies and devices to give people access to the health benefits of sunlight. Our first product - SunBooster - improves mood and boosts energy easily while you work behind your screen or laptop. This fits perfectly into the idea of Good Light Group for improving lives with the right light. More info

The CPD covers Designing Lighting to Promote Better Sleep. It involves an in-depth look at what sleep is, what circadian rhythms are and light’s entrainment of them, the effect of circadian disruption on sleep and the knock-on negative effects of sleep deprivation for general health. Connected with above, shortcomings of many indoor lit environments are discussed, followed by a look at lighting recommendations which can go a long way toward solving these shortcomings. The presentation then moves from the academic to the practicable and shows what an integrative (ie looking at visual and non-visual needs) lighting design process looks like. An example of putting healthy lighting design into practice wraps up the course. More info

Summary of Ulysse Dormoy’s article “What Is Light?” “It occurred to me that since I started posting articles and thoughts about light, I haven’t yet raised the question - ‘ What is Light? ’ – actually, in 30+ years in the lighting industry it's not a question I've challenged myself with.” – Ulysse Dormoy Light exists in a state of duality. It behaves both as a wave and as a particle, a phenomenon known as wave–particle duality. Like the classic “chicken or egg” question, it challenges ideas of origin and cause. Scientifically, light has always been one phenomenon with two inseparable aspects. As a wave, it explains how light propagates and interacts with matter; as a particle, it exists as photons, discrete packets of energy that enable quantum-level interactions. For centuries, scientists debated whether light was a wave or a particle, until early 20th-century quantum theory revealed it to be both. This insight, driven by Einstein and the rise of quantum mechanics, fundamentally reshaped physics, and it’s a surprisingly recent one. In a biological context, this single phenomenon serves two purposes: perception and physiological interaction. Life on Earth evolved under the full solar spectrum, long before vision existed. Light-sensitive cells appeared around 600 million years ago, with true vision evolving roughly 60 million years later. This suggests that light’s energetic, particle-based role may have preceded its visual one. Photons, the particle aspect of light, are central to life. As Geoffrey Guy notes in his book Quantum Biology , the photon may be the most important entity in the story of quantum biology. Yet modern lighting practice largely ignores this, reducing light to a visual tool rather than recognising its full biological power. Since the rise of LEDs, the focus has been almost exclusively on energy efficiency and lumens per watt. Light is treated as something that consumes energy, not something that provides it. Metrics for humans remain visual (lux and lumens), while plants receive energetic metrics (PPFD), solar energy is measured in kilowatt-hours, and food is measured in calories. Why don’t we measure light’s energetic contribution to human wellbeing? Research into quantum biology highlights that different parts of the spectrum play different roles. Visible light fuels life through photosynthesis, while near- and far-infrared light supports mitochondrial function, helping cells produce ATP efficiently, like lubrication for the body’s engine. Regular exposure to these photons may help maintain balance, resilience, and long-term health. Modern lighting and glazing, in the pursuit of efficiency, have effectively “ultra-processed” light, stripping out wavelengths that were deemed inefficient but are biologically vital. Much like ultra-processed food, our indoor light environments may feed us visually but fail to nourish us energetically, especially given that we now spend over 90% of our time indoors. Light’s duality underpins not just vision, but health and vitality. The built environment has been designed almost exclusively for perception, neglecting light’s role in human sustainability. With ageing populations and longer working lives, maintaining health and productivity will be critical, and light has a role to play alongside nutrition, movement, oxygen, and sleep. We’re unlikely to reverse the trend of indoor living. Instead, we need spaces that help restore vitality, through thoughtful design, strategic exposure to biologically meaningful light, or simply by stepping outside for a daily photon shower. Light is not just for vision. It is for health, vitality, and human sustainability.

Effective January 1, 2026, Dave Hollingsbee and Roger Sexton have stepped down from the Board of the Good Light Group. We would like to sincerely thank them for their many years of dedication, support, and valuable contributions to our mission as Board members. Both will continue to support the Group in other capacities. Their commitment has helped significantly strengthen our impact and global reach. At the same time, we are pleased to welcome Ulysse Dormoy , CEO of Atrium , as a new member of the Board. With extensive industry experience, strategic insight, and a strong passion for improving quality of life through better light, Ulysse will further strengthen the Group’s mission. Ulysse commented: “It is an honour to join the Board of the Good Light Group. I have long admired the organisation’s evidence-based commitment to improving human wellbeing through better light. Their mission to raise global awareness of the beneficial effects of good light on body and brain strongly resonates with me, and I look forward to contributing my industry experience and strategic perspective.” We look forward to working with Ulysse and continuing to expand and accelerate the positive impact of good light worldwide.

It’s Blue Monday, often described as the “most depressing day of the year”. Three weeks in the new year, mostly in cloudy, rainy of snowy weather has brought the mood down of many. Photo by Pars Sahin  on Unsplash   Here are some tips and tricks to help you get through this day. Boost your mood naturally Get a lot of daylight: We recommend spending up to two hours outside, especially in the morning. But every short walk outside does already help. Move your body: If you’re going to work out, try to do it near a window so you can get some daylight and enjoy a double boost. Eat well: Choose healthy foods and walk to the shops to buy your groceries instead of taking the car. This way, you’ll get some exercise, fresh air and daylight at the same time.   What if you have to work all day and don’t have time for this? Try to work within one meter of a window so you can benefit from natural daylight. Every 20 minutes, stand up and look out of the window at the sky for 20 seconds. Don’t have a workspace near a window? Consider using a lamp that compensates for the lack of daylight, and make sure it provides at least 500-1000 lux reaching your eyes during the day.

We’ve organised our 23nd Good Light Group meeting. The topics included: Marijke Gordijn  - Light for Public Health Initiative Conor Heaney  - Regulatory and Policy Dimensions of Light for Public Health Ulysse Dormay  – Light & Life, A circular Concept Photo by Artem Beliaikin on Unsplash Missed the Good Light Group Meeting? Watch the presentions online here:  Marijke Gordijn Conor Heaney Ulysse Dormay Want to contact Conor? Please email him at: conor.heaney@icloud.com

A blog by Timo Partonen From November to January, if your exposure to daylight is of 1 hour or longer per day, it is likely that you will not have depressive symptoms during that period of the year. Compared to the conditions where your exposure of less than 1 hour per day, the odds of having depressive symptoms will be 0.72 on average, yielding the confidence interval from 0.60 to 0.82. If you have children younger than 12 years of age at home, it is even more likely that you will not have depressive symptoms from November to January, if your exposure to daylight is of 1 hour or longer per day. These findings, of the total of 23,581 observations, were derived from 10,430 persons living in Sweden (Raza et al. 2024). Self-reports were corroborated by the all-wavelength readouts of solar radiation, with a horizontal resolution of 11 km × 11 km and a temporal resolution of 1 hour. The individual readouts demonstrated that the greater the exposure to solar radiation in residential neighborhood was, the less frequent the depressive symptoms were. I think that this is good news. Because, first, I see that they are generalizable to people living in high latitude regions, and second, they open a way to adapt to climate change. Photo by brooklyn  on Unsplash In high latitude regions, the seasonal variation in natural light is an essential characteristic of the climate. As climate change is already quickly warming up the Arctic and subarctic regions, there will be significant changes in solar radiation as well. Solar radiation is projected, e.g., in northern Finland by the end of this century, to increase by about 5% in summertime and to decrease by 10% to 20% in wintertime. From the perspective of public health, the outcome is likely to turn out negative, if left unnoticed. On the one hand, less solar radiation in wintertime will turn the morning hours darker, which tends to result in greater than usual delays of the circadian pacemaker. It is thereafter likely that sleep disturbance as well as depressive symptoms together with carbohydrate craving in the evening hours will emerge more frequently than as usual. On the other hand, more solar radiation in summertime will turn the evening hours lighter, which leads to greater than usual delays of the circadian pacemaker as well. As a result, more frequent sleep disturbance is likely, such as among 1962 individuals of a cohort of the general population being exposed to greater solar radiation in their residential neighborhood during the past year (Elovainio et al.  2022). Albeit winter depression has been studied for decades and associated with low exposure to daylight, the influence of global radiation on depression remains rather unexplored. There are some reports though. A study from the Netherlands (Sarran et al.  2017), with the total of 23,197 assessments of depressive symptoms weekly during the winter months over six years, included 291 patients having winter depression and living in and near Groningen. It suggested that forecasting sunshine duration or cloud cover might improve the possibilities of early intervention. Another study from Finland (Komulainen et al.  2022) demonstrated that 1845 individuals of a population-based cohort being exposed to greater solar radiation in their residential neighborhood during the past year were less likely to report suicidal thoughts. To adapt to slowly emerging impacts of climate change, we need to rethink, (a) how to design new and renovate old buildings to let daylight come in from outside, (b) how to time artificial light exposures during the day to align with the circadian pacemaker, and (c) how to spend our time in daylight. Future is now, is not it.   Further reading Elovainio M, Komulainen K, Lipsanen J, Partonen T, Pesonen AK, Pulkki-Råback L, Paunio T, Kähönen M, Vahtera J, Virtanen M, Ruuhela R, Hakulinen C, Raitakari O. Long-term cumulative light exposure from the natural environment and sleep: a cohort study. J Sleep Res 2022; 31: e13511. https://doi.org/10.1111/jsr.13511 Komulainen K, Hakulinen C, Lipsanen J, Partonen T, Pulkki-Råback L, Kähönen M, Virtanen M, Ruuhela R, Raitakari O, Elovainio M. Associations of long-term solar insolation with specific depressive symptoms: evidence from a prospective cohort study. J Psychiatr Res 2022; 151: 606–610. https://doi.org/10.1016/j.jpsychires.2022.05.038 Raza A, Partonen T, Hanson LM, Asp M, Engström E, Westerlund H, Halonen JI. Daylight during winters and symptoms of depression and sleep problems: a within-individual analysis. Environ Int 2024; 183: 108413. https://doi.org/10.1016/j.envint.2023.108413 Sarran C, Albers C, Sachon P, Meesters Y. Meteorological analysis of symptom data for people with seasonal affective disorder. Psychiatry Res 2017; 257: 501–505. https://doi.org/10.1016/j.psychres.2017.08.019

Every living organism on earth follows internal 24-hour cycles known as circadian rhythms. From a flower opening at dawn to a surge of human alertness in the mid-morning, these rhythms are deeply embedded in our biology. They regulate countless processes, from gene expression and metabolism to behaviour and sleep. In mammals, the central pacemaker of this system is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN synchronises peripheral clocks that exist in nearly all tissues through neural, hormonal and behavioural signals. Light, especially short-wavelength, blue-white light detected by specialised retinal cells in the eye, serves as the primary environmental cue that entrains the SCN with the Earth’s natural day-night cycle. When our exposure to light and darkness is disrupted, so too are our circadian rhythms. Spending too much time indoors, working night shifts, travelling across time zones or being exposed to artificial light at night can all interfere with this delicate system. Such disruption can lead to a range of metabolic, cognitive and physiological effects. Increasingly, research is showing how circadian misalignment contributes to disease risk, and how understanding temporal biology can guide both medical treatment and lifestyle choices. The circadian clock is therefore not simply a passive timer but a fundamental regulatory system that keeps our internal physiology in tune with the external environment. This short blog is inspired by the book On the Essential Principles and Practice of Circadian Biology: A Road Map  by Roelof A. Hut and William J. Schwartz.

In this episode of the Happier with Light podcast, Lard talks with Jan Denneman, Chairman of the Good Light Group. Jan shares why the organisation was founded and how everything it does is based on science. More than thirty scientific advisors and experts in fields such as chronobiology, neurophysiology, sleep, psychiatry and light, support the group in shaping its message and grounding every insight in solid research. Jan reminds us of something that is often overlooked: most of us think about light only in terms of what we can see. If we can read, work or move around comfortably indoors, we assume the lighting is fine. But that is where the problem begins. Our eyes can perform perfectly well under dim conditions, even when it’s almost dark, while our brains actually need much more light during the day to stay alert, balanced and healthy. Inside our eyes are special light-sensitive cells, the spheres, that send signals not just to the visual part of the brain but also to our internal biological clock and to areas that affect our mood and energy. These cells act as an inner sundial, constantly telling the brain what time of day it is. Based on that information, our brain adjusts hormone levels, deciding when we should feel awake and when it’s time to wind down. The trouble is that indoor light levels are usually far too low, leaving this inner sundial without proper guidance. As a result, many people suffer from sleep problems, low energy and poor concentration. The solution, however, is surprisingly simple. Spend at least two hours a day outdoors, ideally with half an hour in the morning light. When that isn’t possible, sit near a window or use modern LED lighting that mimics natural daylight. Throughout the day, our eyes need at least 500 lux of light to stay in sync with our biological rhythms. Yet most indoor spaces provide only 50 to 100 lux, which is far too little. If we truly want to support human health and wellbeing, we need to rethink how we illuminate our homes, offices and schools. Setting lighting standards to deliver at least 500 lux at eye level would make a real difference. It would allow even those who spend most of their time indoors to experience the benefits of good light — light that not only helps us see, but helps us to live a healthier, better life. Listen on Spotify

Light affects how we sleep, feel, and perform – yet public awareness of its impact remains limited. The Light for Public Health  initiative aims to make evidence-based knowledge on light and health both accessible and actionable, thus turning scientific insight into public benefit. “Light isn’t just for vision – it is a key signal for human biology,” says Manuel Spitschan, research group leader at the Max Planck Institute for Biological Cybernetics and professor at the Technical University of Munich, who chairs Light for Public Health initiative. “By bringing light and health experts together, we can make healthier light an integral part of global health policy and everyday life.” To mark its launch, the initiative has published 26 foundational statements outlining up-to-date expert consensus on how light exposure influences human physiology and behavior. These statements have now been published as an open-access article in the journal BMJ Public Health  and have been translated into 18 languages. The Light for Public Health initiative has emerged from the Ladenburg Roundtable “Light for health and well-being”, a forum for interdisciplinary research dialogue held in April 2024. It is supported by the Light for Public Health Consortium, a network of international experts serving as its scientific advisory body. Participating organizations are: the International Commission on Illumination (Vienna, Austria) the Society for Light, Rhythms and Circadian Health (Philadelphia, PA, USA) the Daylight Academy (Zurich, Switzerland) the Good Light Group (Eindhoven, The Netherlands) the Center for Environmental Therapeutics (New York, USA). Together, they represent leading global scientific institutions advancing healthy light exposure in public health strategies, built environments, and daily life. Foundational statements and further information: www.lightforpublichealth.org

With insights from IALD, WELL, DLA, and leading researchers, this webinar explores daylight-like conditions indoors and their impact on health, design, and circadian well-being. With an increasing evidence base that properties of daylight can positively affect people’s health and well-being, time has come to address the challenge of daylight-like conditions indoors. At present, many people spend time in spaces lit with electric lighting – at work places and in classrooms. How to design the built environment with appropriate light exposure in mind is the topic of a recent white paper by the the International Association of Lighting Designers (IALD) . During this webinar their findings will be presented and commented and contextualized by researchers and practitioners selected by the Daylight Academy, the International WELL Building Institute and the Society of Light, Rhythms and Circadian Health. Introduction by Lisa Wu Light and Human Health: Insights from Hospital Rooms An introduction to the importance of light and human health, with a focus on the hospital room. This introduction will showcase findings from two studies by Lisa and her colleagues, highlighting the important role of light in the hospital environment.  Watch the introduction Lighting Design for Health, Wellbeing and Quality of Light, A Holistic Approach by Kevan Shaw This presentation covers the content of the similarly titled IALD white paper . It covers the current thinking on non visual effects of light and provides some practical guidance on how to incorporate this in the lighting design process. It also includes some more recent information and case studies showing how Integrative Lighting is being applied in real projects. Watch the lecture Panel discussion Panel discussion and the Q&A with the experts: Johannes Zauner Luisa Brotas Nathan Stodola Watch the panel discussion