Urban indoor life reduces our sunlight exposure, while nightlife with artificial lighting and screens disrupts sleep. Both of these factors strongly affect mental health and mortality. Learn how to manage these risks and build a healthy light environment.
Insufficient Light Exposure Leads to Depression and Premature Mortality
Research shows that low light in the first half of a day can be a precursor of depression. German study participants exposed to lower light in the morning showed:
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Higher stress hormone levels
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Reduced sleep time
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Increased sleepiness and sadness levels
A different study conducted in the UK showed that participants spent on average 2.5 hours in the daylight. Each additional hour was associated with:
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Lower risk of major depressive disorder
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Reduced antidepressant usage
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Less anhedonia
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Less frequent low mood
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Lower neuroticism
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Greater happiness
Another UK study showed that darker days influence the cardiometabolic system and are associated with all-cause premature mortality. Light disturbances at night increased that risk even more.
Urban Life in a Dim Light
Urban life greatly influences our light exposure. We work in offices and commute by car or subway. Most of the time we spend indoors where the light exposure ranges from 50 lux to 1,000 lux. While outdoor light exposure starts at 10,000 lux on a rainy day and can reach 100,000 lux in direct sunlight.
Comparison of different light exposures. Source
How to Fix It: Practical Steps to Regain Healthy Light Rhythms
1. Seek bright light early and often
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Aim for at least 2 hours outdoors in the morning or midday. More is better, but even an extra hour counts.
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At home or work, sit near windows or under skylights. If natural light isn’t possible, use daylight lamps up to 10,000 lux.
2. Make your nights darker
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Dim or turn off artificial lights after sunset. Use warm, low-lux lamps, candles, and dimmers.
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Avoid screens for an hour before sleep and use apps that reduce blue light.
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Block external light with blackout curtains and an eye mask.
3. Structure your light and sleep routine
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Keep a consistent sleep-wake schedule.
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Plan to wind down with dim light before bed and expose yourself to bright light immediately after waking.
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