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The long summer evenings are gone, and with fall comes the dark time of the year: by the end of the workday, there is no more daylight. When daylight saving time ends, it may be lighter when you get up, but the evening takes place entirely under artificial light. Whether you’re at your desk, in front of the TV, or scrolling on your phone: it remains artificially bright, even though our bodies are evolved to expect darkness.
Many people are familiar with the consequences of this misguided rhythm: difficulty falling asleep, restless sleep, waking up during the night—and consequently, a lack of energy during the day. However, small steps can go a long way. Here is some background information and the best tips for getting a good night’s sleep with the right lighting.
Natural light changes its composition throughout the day: in the morning and at midday, it contains a lot of high-energy blue light, which wakes us up and promotes concentration. Towards evening, the spectrum shifts: the blue component decreases and the red component increases – a gentle signal that it is time to wind down.
Candles, fires, and the incandescent light bulbs of earlier times also had a similar, warm light spectrum. Collectively, these are referred to as “thermal light sources,” i.e., those in which high temperatures generate light radiation.
Our hormone system reacts very sensitively to this spectral shift. As soon as the blue component in the light decreases, the release of melatonin, the so-called sleep hormone, increases. This is not a switch, but a process: over a period of about two hours, the body slowly slips into night mode—if the light plays along.
Naturally, the light becomes dimmer and warmer in the evening. However, our modern lighting environment is completely different: today, indoor spaces are bright almost around the clock.
It is not only LEDs that emit a high proportion of blue light; computer and cell phone screens also shine directly into the eyes, and even evening kitchen or bathroom lighting is not only brighter but also bluer than a sunset.
This brightness with a blue dominance acts on the body like a continuous daytime signal. Melatonin production is delayed, the pulse remains higher, and the brain remains in its active mode—even though the body is actually tired.
Constant brightness throws our internal clock out of balance. The brain remains in working mode and the body waits in vain for the light signal that triggers nighttime rest.
The role that artificial light plays in our health, on the other hand, has been alarmingly little studied, considering that it is by far the dominant source of light.
Outside, too, the night is no longer dark.
Modern streetlights with cool white LEDs shine efficiently—and brightly. But their light contains precisely those blue components that the body interprets as a signal that it is daytime.
Those who go for a walk in the evening often find it more stimulating than relaxing. The bright light from above hits the hormone-active areas of the retina directly and signals that it is still daytime. Pulse and cortisol levels can rise slightly instead of falling, turning an evening walk into a mini activation program.
What’s more, in many places, too much light enters the house through windows and roller shutter slats. Continuous light at night not only disrupts our rhythm, but also changes the behavior of animals and plants. Nocturnal insects lose their orientation, birds shorten their rest periods—even trees react to continuous lighting with altered growth.
Darkness is a part of the natural environment that we have almost lost. By consciously allowing it back into our lives, we not only protect our own sleep, but also the nocturnal balance of nature.
How light shapes our eyes
You can read more about this, and why daylight and spending time outdoors play a crucial role here, in our article Children’s Eyes and Screentime
It is also worth thinking about light protection in adulthood. Over the course of many years, high-energy light repeatedly hits the same structures of the lens. Oxidative stress can contribute to the lens slowly clouding over—a process that later becomes visible as cataracts.
We also have a detailed article on this issue in our magazine: Blue Light Protection for Lens Health.
In the evening, the body does not need bright light, but rather gentle signals that the day is coming to an end. Warm, dimmed lighting lowers the internal activity level and helps to build up melatonin – the natural hormone for restful sleep.
Even small changes in lighting design can contribute noticeably to relaxation.
Tips for good indoor lighting in the evening:
Warm instead of bright: In the evening, only use warm white, dimmed light sources. Light colors below 3000 K are ideal. Make sure that dimmable light sources do not flicker!
Indirect lighting: Replace ceiling lights and spotlights with table or floor lamps that give off a soft light. Several small light sources create a cozy atmosphere.
Reduce screen time: One hour before bedtime, televisions, computers, and cell phones should be turned off and put away. This also helps you to wind down mentally.
If you have to use a screen: blue light protection glasses protect your eyes when watching TV and using a screen. Dark mode (white text on a black background) also reduces light exposure on the computer, but not everyone finds it comfortable.
Evening rituals: Consciously dim the lights before you get tired—your body will follow suit.
Indoors, we usually have good control over lighting—we can dim it, choose colors, and switch devices off. Outdoors, it’s more difficult. Streetlights, shop windows, and lighting from neighboring houses make the night disappear in many places.
But even if we can’t control outdoor lighting, there are some simple tips that can help.
Tips for dealing with light at night:
Close the blinds: Street lighting acts as a constant wake-up stimulus, even through the window.
Evening walk with a hat: A hat with a brim or a baseball cap protects against direct light from above, which reduces the level of irritation.
Night-friendly home: Only switch on your own outdoor lights when necessary, preferably using motion detectors or timers.
Choose warm white: Where necessary, even in outdoor areas, it is better to use light colors below 3000 K – this creates a calmer atmosphere and is less disruptive at night.
Experience darkness: Black out your bedroom and cover / switch off even small light sources – darkness is part of healthy sleep hygiene.
At the end of the day, we no longer need or tolerate bright artificial lighting. However, it doesn’t have to be immediate, complete darkness, just the right signal.
When the light becomes warmer, weaker, and less blue, the body recognizes that the day is over. Melatonin slowly increases, the metabolism focuses on regeneration, and the internal clock resynchronizes.
This closes the circle: choosing warm, balanced light in the evening and allowing true darkness at night creates the basis for better sleep, stable hormone rhythms, and long-term eye health.
A few reminders for the evening:
Don’t just dim the light, change its tint: warm instead of cool.
Really dark at night – bright again in the morning.
Switching to sleep mode is a process.
Good evening light is no coincidence. It occurs when we consciously bring the day to a close, allowing the light to become warmer and quieter and darkness to become part of our everyday life again. As simple as these routines sound, they are highly effective: the right light spectrum in the evening helps to deepen sleep, relieve strain on the eyes, and stabilize the inner rhythm.
This is because the body needs breaks not only from noise and movement, but also from light. When we give it the chance to truly relax in the evening, our sleep, mood, and vision all benefit.
Image credits:
Titel:
-Coposit-Image from “Candle” by D-Keine/Getty Images Signature via Canva.com
In Text:
-Childrens Hands in Color by shellexx/getty images via Canva.com
-Central Europe Night Lights by nundigital via Canva.com
-Lamp in Living Room by Chris F/Pexels via Canva.com
-Light in Glass Jar by Burak the Weekender/Pexels via Canva.com
-Wooden Walking Path During Sunset by Edgar Bullon’s Images via Canva.com
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