Ein junger Mann genießt das Tageslicht draußen. Er lächelt und ist von Bäumen und Blumen umgeben. Licht ist gut für psychische Gesundheit.

Light and Mental Health

In the middle of summer, when the days are long and the sunlight is bright, we often feel energized and happy. But how much does light really influence our mental health? And what happens if we don’t get enough daylight or are exposed to too much artificial light? In this blog post, we take a look at the scientific findings on this topic and provide practical tips for a healthy use of light.

Eine Frau sitzt in hellem Tageslicht und meditiert. Das Thema ist Licht und psychische Gesundheit
Light affects our mood. There is a reason why people speak of "light mood" or "dark mood" when they want to describe a good or bad mood.

A Difference Like Night and Day

How Light Affects Our Mood

An impressive study was published in the fall of 2023: using data from over 85,000 participants, it examined the influence of light on mental health. The results are clear:

Exposure to light at night increases the risk of depression, anxiety disorders, PTSD, psychosis and self-injurious behavior. In particular, people who are exposed to a lot of artificial light at night show significantly higher rates of these mental disorders.

In contrast, an increased exposure to daylight can reduce these risks. The study showed that participants who regularly spent time outdoors during the day were significantly less likely to suffer from these mental illnesses.

This study highlights the central role that light plays in our daily lives – not only for our physical health, but also for our mental health. Given that we spend much of our lives indoors and are often exposed to artificial light, it is important to understand how we can optimize our lighting environment to protect and promote our mental health.

Light Sets the Mood

Many Mechanisms and one Conclusion

How can light have such a strong effect on our well-being? Perhaps it helps to realize that evolution has perfectly equipped us to function in a natural light environment: Outdoors in daylight during the day, and in the dark at night. In terms of human history, even fire is a fairly recent achievement, not to mention candles and electric light.

Daylight, for example, stimulates the production of serotonin. This not only makes us happy, but also alert and focused – ideal for hunting or remembering where the best berries grow. Sunlight also promotes the formation of vitamin D, which is important not only for our immune system, but also influences our mood.

However, we are simply not made for artificial light in the evening and at night. The blue-heavy light from screens and energy-saving lamps in particular suppresses the production of the sleep hormone melatonin. Poor sleep is itself a risk factor for mental disorders.

In addition, there are certainly other correlations that can explain the results. For example, daylight is often a marker for outdoor exercise, which is known to alleviate anxiety and depression. A lot of artificial light at night, on the other hand, can indicate problematic media use, which of course also affects mental health.

Overall, however, the studies show quite clearly that a natural light rhythm is the best thing we can do for our mental health.

Tageslicht und Nachtlicht. Ein Bild zeigt die Lichtstimmung einer Stadt im Verlauf des Tages. Es geht um Licht und psychische Gesundheit.
As you can see here, the night is no longer dark. We have a separate, detailed article on night-time light pollution in our magazine:

A natural light rhythm - plenty of daylight and minimal artificial light at night - is the best thing we can do for our mental health.

Use of Light in Therapy

Light is already used therapeutically in a variety of ways. Light therapy is particularly well known for seasonal affective disorder (SAD), which occurs during the dark winter months. Patients are exposed to intense artificial light that simulates daylight for a certain period of time every day to alleviate the symptoms of depression.

Light therapy is also used for other forms of depression as well as for sleep disorders. Studies have shown that this form of treatment lifts the mood, improves sleep problems and stabilizes the circadian rhythm. The effectiveness of light therapy is well documented and is recommended by many experts.

Studies at a Glance

Light by Day and by Night

This comprehensive study with over 85,000 participants investigated the influence of light on mental health. It found that exposure to light at night increases the risk of depression, anxiety disorders, PTSD, psychosis and self-injurious behavior. In turn, it was shown that more daylight can reduce the same risks.

Light at Night and Mental Health

This meta-analysis examines the relationship between artificial light at night and mental disorders. The studies included use satellite data to measure outdoor lighting as well as brightness readings taken in bedrooms.

Daylight Combats Winter Depression

This analysis of 3 long-term studies from Sweden showed that a higher dose of daylight in winter reduces the risk of depression symptoms and sleep problems. Participants who were outside for at least one hour a day reported fewer depressive symptoms.

Conclusion and Useful Tips for Everyday

Light plays a central role in our mental health. Research clearly shows that a natural light rhythm – plenty of daylight and little artificial light at night – is best for our well-being. Even though modern life mainly takes place indoors and we can hardly avoid artificial light and screens, we can still make use of these findings.

Here are some simple tips on how you can integrate the positive effects of light into your everyday life while avoiding the negative effects:

  1. Enjoy the fresh air: try to spend at least one hour outside in daylight every day. A walk during your lunch break can work wonders. Daylight also has positive effects when the sky is gray and even when it rains.
  2. Reduce screen time in the evening: Minimize the use of screens, especially in the afternoon and night. Media use in the evening doesn’t just keep us awake because it excites and distracts us. Screen light also contributes to night-time light exposure, which has been linked to mental health problems.
  3. Use blue light protection: As the blue component from screens and ambient light in particular disrupts the internal clock, our blue light protection glasses with their powerful BluelightProtect filters can help.
  4. Create a relaxed sleeping environment: make sure your bedroom is dark and quiet. Avoid bright light before going to bed and block out street lighting with blinds or dark curtains.

Discover more


Discover our blue light protection glasses