The invention of electric light was a real revolution for us as human beings. It allowed us to disconnect our work and lives from a normal day/night rhythm. However, it also caused and continues to cause us to cause some negative health effects. 

After all, light is our daily zeitgeber, our daily pacemaker. Natural daylight synchronises our biological clock. It regulates our biorhythms to a great extent and thus... also our sleep. It is not for nothing that the WHO today describes night work as a particular risk. Disrupting our biorhythms is today associated with cancer, but also with sleep disorders, reduces our cognitive performance, etc.

We spend 90% of our time indoors

Our daily habits are also evolving. We spend more and more of our time inside buildings, at work and at home, which often makes the impact of the above even worse. We often also have the bad habit of immersing ourselves in light from smartphones and tablets in the evening. In many cases there really is jet lag, a shift in our biorhythms.

 Nevertheless, most of our standards regarding light in the workplace focus on the visual domain, sufficient light to be able to see, to be able to perform our task well. The latest review of EN12464-1 in August 2021 fortunately offers some recommendations, but these are still not part of the real standard. Other systems such as the International WELL Building Standard are fortunately also taking clear steps in the direction of the non-visual area. Light that we need, not only to be able to see, but also to be able to function.

More light!

One of the things where there is a clear consensus is that we need more light during the day. We often don't realise it, but during the day we only get about half the percentage of light that we get outside, even on a cloudy day. In other words, the difference between indoor light and natural daylight outside is very big.

Our view of this today is often additionally clouded by our hunger for energy savings. A race to the bottom for the shortest payback period, but which unfortunately often no longer takes into account the quality of the light to which we are exposed.

Science has taught us since the early 2000s that, in addition to the classic rods and cones, our eye also contains a receptor for these non-visual stimuli of light, the ipRGCs. The latter receptors capture information and transmit it to the suprachiasmatic nucleus in our brain, the central pacemaker for our biorhythm. Our biorhythm, or circadian rhythm, also has a length of about 24 hours and requires daily synchronisation.

Sufficient daylight. Go outside.

One of the most important recommendations from many studies starts with a simple advice: clear days and dark nights. The design of buildings should therefore take into account the maximum amount of daylight and the most favourable location of workplaces with respect to daylight. Spend as much time as possible outside during the day. Simple but very sound lighting advice.

A list of 7 tips

Since we as humans like to have lists, I am also listing below some recent recommendations from research by CIBSE and BRE Research :

1. Between 10 a.m. and 2 p.m., maintain higher than normal light levels with a light spectrum that also contains some blue light. A new unit of measurement, MEDI or melanopic lux, is expected to be introduced here. The recommendation here is 250 MEDI lux during normal office hours, for anyone working inside a building. To be continued.
2. Reduce the light towards the end of the day and also lower the colour temperature to warmer light. Concretely, light colours of the type 4000K are for our workplace, at home we should use 2700K as light colour and dimmed.
3. Make maximum use of ceilings and walls to reflect light. So use light colours to furnish your office. Although black is now a fashionable colour in offices, unfortunately it has a detrimental effect on the way we experience light. The use of floor lamps, with indirect light upwards, and the use of lights on the wall is making a comeback.
4. Use good quality LED lighting for your workstation to avoid glare and flickering of light. Also visually balance your immediate surroundings and avoid very light-coloured reflective work surfaces. A matt worktop is the best choice, but a matt pad can also do the job.
5. If possible, vary the lighting during the day in a very smooth manner. Reliable control is a must in order not to disturb the user's comfort.
6. There is also a human factor to light. The experience is often different for everyone. It is not always obvious, but where the opportunity exists, there is a clear preference for individual, personal control of the light one works under.
7. Last but not least, raise awareness. Explain to users how a lighting system works, why it is so important.

Do you have any questions about light at your workplace? Then don't hesitate to contact us. We are happy to help.