A blog post by Dr. Aida Farshadi For millions of years, humans lived under the full spectrum of sunlight. Our physiology evolved not just with visible light, but also with near-infrared light (NIR), an invisible wavelength that makes up nearly half of the sun's energy reaching Earth. Photo by Todd Rhines  on Unsplash What is near-infrared light and why we're missing it? Near-infrared sits just beyond the red end of the visible spectrum, in the 700–1100 nm wavelength range. Un

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, fo

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,

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 c

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 ,

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 goi

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 yo

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 ex

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: mos

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 Techni

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

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 pre

It’s almost the time of the year again, the day in autumn when the clocks turn back to natural time. Every year, millions of people groan, lose sleep, and wonder, why are we still changing our clocks to daylight saving time in the summer? The seasonal clock change is one of those traditions that perhaps made sense once upon a time but no longer serves us. In fact, modern science is increasingly clear: switching the clocks twice a year disrupts our health, our productivity, an

Good light changes lives. A peer-reviewed study “ Biodynamic lighting effects on the sleep pattern of people with dementia ” reports that good light, either daylight or light that compensates for a lack of daylight, has a substantially positive influence on people with dementia. The results are both humane and practical: better sleep at night, greater alertness by day, and less restlessness overall. What the research found Under good light conditions, residents experienced: L

Together with the  Society for Light, Rhythms, and Circadian  Health (SLRCH) , the  Daylight Academy (DLA) , the  International Association of Lighting Designers  (IALD) and  Luger Research (LR) , we are organising and presenting the ‘deLIGHTed Talks’ lecture series. The lectures are free to attend. SAVE THE DATE: 3 November 2025 (3 PM CET) Register here With insights from IALD, WELL, DLA, and leading researchers, this webinar explores daylight-like conditions indoors and the

In this episode we’ll be focusing on how to measure light. To guide us through this topic, we’ve invited Hedy Lee from UPRtek, a...

We are very pleased to announce that Lawrence Lin has joined our board as a new member! Lawrence is an innovative LED & lighting expert,...

Our increasing recognition of the effects of light on circadian clocks and rhythms is fueling exciting applications in agriculture,...

Lighting is often treated like background scenery. Yet it quietly shapes energy use, cognitive performance, sleep quality, and even the...