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Annual SLTBR Meeting

20-22 June, 2024

Prague, Czech Republic

35th Annual SLTBR Meeting
  • Engage with the latest research and developments in light treatment and circadian health

  • Network with professionals and researchers from around the world

  • Enjoy the historical and cultural charm of Prague

More info


The meaning of light in the workplace

26 June, 14.30 CEST, 2024

Atrium, London

The Meaning of Light in the Workplace: Implications for health and wellbeing beyond the circadian rhythm
  • A Workplace Trends Masterclass with

  • Glenn Jeffery, University College London

  • Bob Fosbury, University College London

  • Ulysse Dormoy, Atrium  

More info

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Good Light Group meeting #19

30 April, 16.00 CEST, 2024


Good Light Group Meeting #19

Regularly, we organize group meetings with distinguished speakers to explore new research, fascinating developments, groundbreaking innovations, or interesting projects all related to good light.


  1. Research into the acceptance and effectiveness of task lighting for non-image forming effects of light with ​Roger Sexton, Stoane Lighting and professor Peter Raynham, Emeritus Professor of the Lit Environment, UCL Institute for Environmental Design and Engineering (IEDE)

  2. Updated guide for general public

deLIGHTed Talks #7: Time Matters - Shining Light on Metabolic Health​

The Good Light Group, together with the Society for Light Treatment and Biological Rhythms (SLTBR), the Daylight Academy (DLA), and Luger Research (LR), are organizing and presenting the “deLIGHTed Talks” lectures.

Watch the presentations

Good Light Group meeting #17

Regularly, we organize group meetings with distinguished speakers to explore new research, fascinating developments, groundbreaking innovations, or interesting projects all related to good light.


  • Good light news.

  • Lighting the Path to Well-Being: Three Decades of Light Therapy with Lumie - Malgo Kenyon, Head of brand and marketing Lumie.

  • The clock with thousand hands - Marijke Gordijn, board member GLG & Anneloes Opperhuizen, science advisor GLG.

Watch presentations

Daylight Awareness Week​


Daylight and us: learning from the past?

This year, the Daylight Awareness Week celebrates daylight thanks to different kinds of contributions and formats, published throughout the week.

An event organised by the Daylight Academy.

The Daylight Academy promotes international and interdisciplinary cooperation among scientists, architects and other professionals involved in daylight research or with a strong interest in daylight related topics.

More info

deLIGHTed talks 6th edition: History of good light - beyond the visual spectrum
15 November, 15:00 - 16:30 CET

The Good Light Group, together with the Society for Light Treatment and Biological Rhythms (SLTBR), the Daylight Academy (DLA), and Luger Research (LR), are organizing and presenting the “deLIGHTed Talks” lectures.

The lectures are free to join.

This webinar will take place as part of the Daylight Awareness Week 2023 of the Daylight Academy.

Watch all lectures here


6 October 2023

13.30 CEST

Straevenweg 11, Weert

NSVV Inspiration Table: Why does light colour require knowledge of new techniques?


Colour and light have a significant impact on human health, but can we use light to make all colours? How does a particular colour affect our productivity and concentration and our sleep-wake rhythm?

NSVV will have these questions answered by experts on light, colour and health on 6 October. 


Jan Denneman will present: 'The importance of light colour for human health'

Click here for more information

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26 September 2023

16.00 CEST


Good Light Group meeting #16

From time to time, we organize a group meeting with distinguished speakers to explore new research, fascinating developments, groundbreaking innovations, or interesting projects all related to light.

You can now view an update of the Good Light Group and the presentations by Oliver Stefani and Adrià Huguet-Ferran

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28 June 2023


Good light for healthier and happier people in the workplace

​Our board member Jan Denneman was asked to give a presentation about good light by VZW Groen Licht Vlaanderen, about how light affects people.

More info

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27 June 2023

16.00 CEST


15th Good Light Group meeting

  1. Sarah Morgan and JoAnn McKeown -

    the return on investment of good Light, Sarah, founder and CEO of participant NanoLit and JoAnn will discuss how we can sell good light. Watch here

  2. Oliver Stefani –  the Daylight Academy. Oliver, one of our science advisors and owner of Chronolight, will explain how the Daylight Academy (DLA) is organized, and its activities. Watch here


1 - 2 June 2023



DLA - Annual Conference 2023


This year’s edition will focus on the rhythms of daylight and how they shape life across seasons and latitudes. By combining a variety of disciplines and perspectives, the DLA Annual Conference 2023 intends to explore several aspects of this subject, from the biological adaptations to different photoperiods to the psychological and cultural differences across latitudes.

More info


30 May - 1 June 2023



SLTBR 2023 - 34th Annual Meeting 


The upcoming meeting spans three days and features a lineup of impressive speakers. Attendees will also have the chance to preview the Lighten Up! exhibition. The event will take place in Lausanne, a charming city known for its French-Swiss flair. Situated on Lake Geneva, the city offers breathtaking vistas of the Savoy Alps.

Click here for more info

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16 May 2023

16.00 CEST


deLIGHTed talks #5
Mimicking Daylight Indoors



by Aicha Diakite-Kortlever, TU Berlin

Daylight – See me, feel me, touch me, heal me!

by Yvonne de Kort, TU Eindhoven


Daylight in buildings – How much we need and get

by Joannes  Zauner, Hochschule Münich


Panel discussion Daylight inside​


More info

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7 April 2023

9.30 CEST

Scheltema Leiden

Dutch chronobiology meeting

Bioclock consortium wants to gather all chronobiologists to create a full day symposium on the breadth and depth of research on circadian biology and biological rhythms that takes place in the Netherlands.

More info

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21 March 2023

16.00 CET


14th Good Light Group meeting

1. Good Light news

2. Introduction new board members

3. Joachim Stormy Hansen

“Measuring and logging good light”

Joachim, one of our science advisors and related to participant Ocutune will explain initiatives on how to measure how much (good) light people do actually receive

Watch all presentations here

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25 January 2023

16.00 CET


4th Good Light Group Counsil meeting
  1. Review 2022 activities including financial report​

  2. Policy & operational plan 2023 – Jan Denneman​

  3. Group picture & break

  4. Social-economic impact of good light and of “not good light” – Bruno Smets

    • Introduction

    • Mentimeter dialogue

    • Next steps


Activities of the Good Light group in 2022

Plans for 2023

Socio-economic impact of good light


23 November 2022


Future Lighting 2022

Easyfairs Netherlands is launching the event Future Lighting at Next Level at Evenementenhal Gorinchem on Wednesday 23 and Thursday 24 November.

Jan denneman will speak on the subject:
Good light: the missing link between energy saving and occupant health.

Click here for more information

Click here for the interview

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3 November 2022


deLIGHTed Talks #4
Good Light – Balancing Health and Energy

The Good Light Group, together with the Society for Light Treatment and Biological Rhythms (SLTBR)the Daylight Academy (DLA)the International Association of Lighting Designers (IALD), and Luger Research (LR), organized and presented the “Good Light – Balancing Health and Energy” lectures. The webinar explains the need for a day with Good Light and how we are able to balance health and energy issues in lighting designs.

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11 October 2022

 De Achelse Kluis - Netherlands

Smart Office 2 | 11 October

Discover how to combine workplace reservations & smart lighting to run as an efficient organisation every day. A supplement to Smart Office 1.


Jan Denneman will talk about the topic:
"Learn how the health and well-being of employees can be improved through good workplace lighting."

More info

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22 September 2022



For three years in a row, the Good Light Group and LED Expo Thailand have been partners of SMARTTECH ASEAN. This year we have been invited again to present the Good Light story at their educational symposium which took place on September 22.

The main topics were:

  • Good indoor light for better health

  •  Guide to good light

  • The innovation challenge


More info here

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20 - 21 September 2022

 Zuidas Amsterdam


Real estate future proof festival. Two days about the future of the construction and real estate world.

Board member Jan Denneman presented the keynote speech: “the health effects of good light indoors” and shared a panel with Marijke Gordijn, Erna van het Erve and Maarten Voorhuis.

Click here for more information


15 - 19 August 2022

 Chexbres, Switzerland

Summer School “Measuring Light and Illumination”

Using Horace Bénédict de Saussure’s cyanometer (1789) for measuring the colour of the sky as a starting point, for people to develop an interdisciplinary understanding of measurement and characterisation of light and illumination. This residential summer school combined lectures, practical workshops, an excursion and a student-led research project.

Click here for more information

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June 28th 2022

16.00 - 17.00 CEST


11th Good Light Group meeting



  1. Good Light news

  2. Renske Lok – Stanford University & Science Advisor Impact of daytime illuminance on cognitive functioning and alertness

  3. Merijn Wegdam – Sunshower - Low dose UV for healthy vitamin D level in wintertime

  4. 12th group meeting proposal: Tuesday 20 September 2022, 16:00hr CEST and volunteers to present

More information here


June 23rd - 25th 2022


United Kingdom

SLTBR 2022 - 33rd Annual Meeting


The program committee of SLTBR prepared an excellent program with three symposia dedicated to fundamental, applied and clinical new insights. The CME course was filled with lectures on the current status of the use of melatonin.

In addition, they organized a young scientists symposium, a poster session with wine & cheese, and, of course, a banquet.

Click here for more information


June 23rd 2022

16.00 - 17.00 CEST


Holiday feeling and better health throughout the year


Signify's Lighting Academy is a learning platform that offers all relevant educational resources.

On thursday June 23 at 16.00 Jan Denneman talked about how light influences our body.

More information


June 7th 2022

15.00 - 16.00 CEST

SunLED free webinar


Seaborough has developed and patented technology that can easily be integrated into everyday lighting products.

The SunLED technology was explained by:

  • Pieter Six - CEO of Seaborough

  • Dr. Anne Berends - Program Director SunLED

  • Dr. Marijke Gordijn - CEO Chrono@Work; expert on effects of light on health

  • Owen Zachariasse - Senior Director JLL Work Dynamics

More information

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May 24th 2022

15.00 - 16.30 CEST


deLIGHTed talks #3 
The Right Light at the Right Time – Bright Days, Dark Nights


The Good Light Group, together with the Society for Light Treatment and Biological Rhythms (SLTBR)the Daylight Academy (DLA)the International Association of Lighting Designers (IALD), and Luger Research (LR), organized and presented the “The Right Light at the Right Time – Bright Days, Dark Nights” lectures. The webinar explained the need for a good day and night light based on scientific evidence and practical experience.

More info


May 21st - 22nd 2022

15.00 CEST

Nature Bits

Nature Bit 'Dark Sky' Texel

Nightlife from different perspectives.

Did you ever think about experiencing the night through the eyes of a bat? Or how (artificial) light influences your biological clock, sleep rhythm and energy levels?

If so, join Nature Bit to one of the last places where the milky way can be observed in the Netherlands and learn about the effects of light and darkness on nightlife and humans.

More info

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May 10th - 12th 2022

18.00 - 19.30 CEST


Daylight Awareness Week 2022


The third edition of the virtual “Daylight Awareness Week” is organised in the context of the UNESCO International Day of Light and is aimed at the general public as well as experts and students interested in daylight research.

The program and further information will be communicated soon.

April 26th 2022

16.00 - 17.00 CET


10th Good Light Group meeting


The 10th Good Light Group meeting was on the 26th of April.



  1. Anne Berends - Seaborough - Beyond the visible: SunLED brings inside the healthy near-infrared part of sunlight.

  2. Daniel Tschofen – Wirklicht - What are the luminaires of the future?

  3. Inge Declercq – neurologist, sleep expert, SleepWell & StressLess, UZAntwerpen - Brainstorm on idea for citizen science project & looking for partners.


March 25th 2022


Defining the characteristics of healthy lighting: From discovery biology to real-world application


A webinar of UK Health Security Agency

We are exposed to levels of light at night far beyond the range of star- or moon-light, while indoor lighting during the day provides a poor approximation of the intensity and spectrum of natural daylight.


Professor Robert Lucas

Timothy Brown

February 24th 2022

13.00 - 14.00 CET


9th Good Light Group meeting


The 9th participant meeting was held on Thursday February 24th.



  1. Nicholas Witton – Elite Sleep
    How the combination of a lack of daylight can lead to sleep deprivation and Social Jet Lag which affects alertness, productivity and result in lower performances 

  2. Oliver Stefani – Chronolight
    What is Chronolight? Chronolight uses scientific findings on light effects and offers advice on good lighting.

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January 27th 2022

9.00 - 12.00 CET


3rd participant council meeting

Thursday January 27th we organized the 3rd participant council meeting, which was also the 8th participant meeting.

The meeting was all about movements and how to start one.

December 16th 2021

14.30 - 17.30 CET


Enlighten me Conference

International Conference
Shaping light for health and wellbeing in cities

Our boardmember Jan Denneman talked about

artificial lighting ad its implications for health, wellbeing and the circadian rhythm 

See presentation

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November 4th 2021

13.30 - 14.30 CET


7th participant meeting

From time to time the Good Light Group organizes a meeting for all the participants & partners. Organizations who joined the Good Light Group tell something about their business and latest developments.


  • Good Light news​

  • Wilfried Pohl - Bartenbach

    Title comes later

  • Mikolaj Przybyla – GLOPTIC

    Lighting audit issues​

Second deLIGHTed talks webinar

The Good Light Group, together with the Society for Light Treatment and Biological Rhythms (SLTBR)the Daylight Academy (DLA)the International Association of Lighting Designers (IALD), and Luger Research (LR), organized and presented the second deLIGHTed talks webinar.

The webinar explained what the negative effects of daylight saving time are and how to cope with the dark period of the year.



More information

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October 21st 2021

17:00 - 18:00 CEST


Comic book “Enlighten your clock” – Launch event and expert talk

Published this spring in English, the comic book Enlighten your clock: How your body tells time describes with intelligence and humour the effects of light on our body. To celebrate this success, the Daylight Academy hosted this “Launch event & expert talk”. Special guest Daniel Smith shared his views about sleep, light and mental health in teenagers.

Watch the talk here




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October 14th 2021

20:00 - 21:00 CEST


What is Good Light?​

You can now watch the webinar 'What is good light?' online organized by Reliable Lighting Solutions. Here you can listen to our founders Marijke Gordijn and Jan Denneman talk about Good Light.


What is Good Light, and why do we need it?
How does light affect our physical and mental health?
What can we do to bring good light into our spaces?

Registration for this event is limited to 75 participants so don’t delay.

Watch it here


October 6th 2021

09:00 - 17:30 CEST

High Tech Campus

Strategy Day​

Second strategy meeting.


September 15th 2021

09:00 - 09:30 CEST


Good Light for Health and Wellbeing​

LED Expo Thailand and SMARTECH ASEAN 2021 organized a free webinar on zoom.

The main topics were:

  • Energy Efficiency by Digitalization & Technology

  •  Smart Lighting, IoT & Connectivity

  •  Sustainability and Environment

  •  Health & Wellbeing


In the first presentation of the session Health & Wellbeing, our board member Jan Denneman explained the guidelines for Good Light.


Watch the webinar here


August 31st 2021

13:30 - 14:30 CEST


6th participant & partner meeting 

Every period the Good Light Group organizes a meeting for all our participants & partners. New organizations who joined the Good Light Group tell something about their business and newest developments. 

Agenda August 31st:

1.    Good Light news
2.    Pieter Bax – Luxlight, the Netherlands
Good Light via skylights
3.    Floris Wouterson – Floris Wouterson Sleep Performance 
Factors for a good sleep and the influence of good light
4.    Next meeting and volunteers to present
5.    Closure


July 6th 2021

09:00 - 11:00 CEST and

July 13th 2021

16:00 - 18:00 CEST


Online tutorial on the understanding and application of CIE S 026:2018

This CIE Tutorial has been developed to support the understanding, adoption and proper application of CIE S 026/E:2018 CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light.



More information

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May 25th 2021

09:00 - 10:00 CEST


5th Participant & Partner Meeting


We organized the 5th participant and partner meeting. With lectures of:


Dr. Luc Schlangen – Eindhoven, University of Technology
Advances in Lighting Metrology and Non-Visual Effects of Light.


Mrs. Cristina Tanase – Signify – Nature Connect
Bringing the natural light indoors with NatureConnect by Signify.​

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May 19th - 21st 2021


SLTBR's 32     annual meeting  

On behalf of the board of directors of the Society for Light Treatment and Biological Rhythms (SLTBR), they invited you to the society's first online congress.  With the generous support of their sponsors and industrial partners, this congress will be free of charge for all registered participants.

The topics that were discussed are : Photoreception, Lighting and Health. 

More information about the program and registration


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May 14th 2021

09:30 - 10:30 CEST


The unused potential of good light indoors

LED Expo Thailand and SMARTECH ASEAN 2021 organized a free webinar on zoom.

The main topics were:

- The problems of billions of people in biological darkness

- What is Good Light?

- The unused potential and business opportunity of good light

- Discovery 2002: Spheres (ipRGGs) synchronize biological clock 

- The advantages of Good Light & 'healthy buildings'

Watch the webinar here


March 23rd 2021

09:50 - 10:50 CET


LICHT 2021

From 21 to 24 march 2021, the European Light Congress in Germany took place as a complete online event. See Startseite | LICHT2021. The Good Light Group participated in the panel discussion about sustainable good light on Tuesday March 23, from 09:30 – 10:50.


See Nachhaltiges gutes Licht | LICHT2021

Light Symposium Wismar 2020/21

The digital lighting conference in Wismar took place online this year. The topic is very much related to the mission of the Good Light Group: “The future of daylight and artificial lighting in healthy built environments”.

Click here for the programme

March 10th - 12th 2021


SLL Webinar: Good indoor light makes people healthy and happy

The webinar began with a presentation from Jan, followed by a panel discussion with SLL President Elect, Dr Ruth Kelly Waskett and Professor Peter Raynham. There was also an opportunity for audience Q&A.

Click here for more information

March 10th 2021

12:00 CET


Online Lighting Fair Japan - Tokyo

There were several on-line lectures about Human Centric Lighting during this event. Christian Cajochen and Dorothy Sitt presented scientific backgrounds of how good light affects our body clock. Jan Denneman presented a lecture titled “the unused potential of good light indoors”.

Click here for all lectures

March 9th 2021

02:30 CET


Non-visual effects of light and its application in architecture

PhD Steven W. Lockley, an associate professor of medicine, Harvard medical school neuroscientist, Brigham & Women’s hospital professor and VC fellow was presenting a webinar about non-visual effects of light and its applications in architecture, organized by the SLTBR.

Watch the full webinar here: Non-visual effects of light and its application in architecture

February 17th 2021

17:00 CET


Second annual Participant Council meeting

On 28 January our board members and participants met online for the second Participant Council meeting. Representatives of 15 companies / universities were present.

More information: Second annual Participant Council meeting

January 28th 2021

9:00 CET


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Good Light indoors makes people healthy and happy

Presented by Mr. Jan Denneman, Chairman of the non-profit organization Good Light Group and Honorary Ambassador of the Global Lighting Association.

You can watch the full webinar here:

Good Light indoors makes people healthy and happy

January 21th 2021

15:00 CET



Chronotherapeutic treatments

Webinar organized by the SLTBR, by John Gottlieb, MD assistant professor at Northwestern University, Chicago USA.

You can watch the full webinar here:

John Gottlieb Chronotherapeutic Treatments

January 20th 2021

19:00 - 20:00 CET


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