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Putting light users first: health, well-being and socio-economic impact

Our Chairman Jan Denneman wrote a commentary about putting light users first for the magazine Led professional Review. Here is a short summery about the article.


Indoor lighting significantly affects our health and well-being. The scientific community is very clear, indoors we receive insufficient daylight during the day while we experience too much artificial light in the evening and at night. This disrupts our biological clock, leading to poor sleep, reduced productivity, and this affects our physical and mental health.



Studies highlight the crucial role of light in our overall well-being. Light-sensitive cells called ipRGCs have been discovered in the retina. These cells, unrelated to vision, are connected to our brain's mood center and biological clock. By responding to the right patterns of light and darkness, they synchronize our biological clock to the 24-hour cycle.

The importance of light was recognized through the Nobel Prize in Physiology or Medicine in 2017. This award celebrated scientists' breakthroughs in understanding how light impacts our biological clock and, consequently, our health.


Experts recommend a minimum of 250 Melanopic Equivalent Daylight Illuminance (m-EDI lux) during the day to effectively influence our biological clock. However, most indoor spaces fall significantly short of providing this recommended amount. Excessive artificial light exposure during the evening and at night further exacerbates the issue.

These recommendations, following peer reviews, were officially published in March 2022. The draft standard ISO 8995 for indoor lighting mentions these recommendations in Annex B.5, although annexes are often overlooked.


the main arguments for lighting focus on costs and return on investment based on energy savings, primarily benefiting building owners and facility managers. But how much money can be saved when people are fit and alert at work, have fewer absences, function optimally, don’t experience depressive feelings, and are less frequently ill? How much can society save on healthcare costs? These amounts far exceed the energy savings from lighting.


By prioritizing the health and well-being of building users, we can pave the way for healthier and happier lives. Billions of people are engaged in indoor activities during the day, deprived of natural daylight and reliant on artificial light, will get a healthier and happier life.


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