• Sabi Kiesel

How (day)light and sleep are related

The natural sunlight follows a simple rhythm. In the early hours there is sunrise with a very warm colour temperature. During the morning this red tone changes into yellowish and reaches a highest blue tone around noon time. In the afternoon the light then changes back to the yellowish and finally red tone with sunset until the darkness comes in.



Our human body follows this daylight pattern. This is called circadian rhythm and it regulates our sleep-wake cycle. In my previous post I shortly described how artificial blue light affects our sleep. Exposed to blue light in the evening and night times stops our melatonin production in the body (which naturally prepares us for sleep) and causes sleep problems. Constantly exposed at the wrong times it can affect our health.


F.lux software during day
F.lux software during bed time











To maintain a natural rhythm I strongly advice to avoid blue light nearer to sleeping time. If you cannot avoid to be on a screen like laptop or phone, there are softwares like 'f.lux' for computers or 'Night Shift' on iPhone settings etc. which help to turn the screen colour from a blue-ish bright to a warm orange and so does not interrupt your natural melatonin production. You might as well adjust the TV colour tone to a warm tone at these times. Or at least have a warm light e.g. freestanding luminaire next to the TV to neutralize the very blue bright standard light from the TV a bit.


Under bed night lights © hammacher.com
Under basin night lights © hammacher.com















What if waking up during night time? You know the feeling too well, turning on your phone to check the time and/or going to toilet switching on the full light and bang it is so hard to fall asleep again. Once again it is the colour temperature of the artificial light we are exposed to. Try to have a specific low level night light e.g. sensor activated LED strip underneath bed and bathroom basin or at least a night table lamp in bed and bathroom with a very warm colour temperature of about 2200K close to the orange colour. That avoids your melatonin productin being stopped and you are not blinded in the night. Easily your body can go back to sleep in no time.


I wish you happy orange night times!


#circadianrhythm #nightlight #melatoninproduction #orangelight #naturalsunlight #healthylight #lightingdesign

5 views

© 2020 by Urban Spectrum Design