Your Body Needs Darkness: How Light Pollution Disrupts Sleep
When the sun goes down, does your environment actually get dark?
For most of human history, the answer was yes. Today, darkness has almost disappeared. We have televisions glowing across the room, phones inches from our faces, tablets in bed, streetlights outside our windows, and bright indoor lighting long after sunset. We've changed our light environment dramatically. But our biology still pays attention to the sun.
Light Is a Signal
Your body operates according to a roughly 24-hour internal clock known as your circadian rhythm. Light is one of the most important signals helping regulate that clock. Bright daytime light tells your body it's time to be alert and active. As evening approaches and your environment becomes darker, your brain receives a very different message: the day is ending. That transition helps your body prepare for sleep, including the normal evening rise in melatonin. The problem is that modern life can confuse the signal.
When Night Starts Looking Like Day
Blue-enriched light is naturally abundant during daylight hours. But we can now expose ourselves to similar wavelengths long after sunset through screens and many forms of artificial lighting. That doesn't mean blue light itself is "bad."
Timing matters. Light that helps promote alertness during the day isn't necessarily the signal you want your brain receiving when you're preparing for bed. Late-night light exposure can suppress or delay melatonin and shift circadian timing, potentially making it harder to fall asleep and maintain a consistent sleep schedule.
Bring Back the Night
You don't need to spend your evenings sitting in complete darkness. Instead, start giving your body clearer signals. Get outside and experience natural light during the day, particularly in the morning. As bedtime approaches, dim bright indoor lighting. Reduce unnecessary screen time. Keep your bedroom as dark as practical. These are simple changes that don't require another supplement or expensive health device. Sometimes supporting health starts with restoring something humans had naturally for thousands of years: Bright days. Dark nights. Consistent rhythms.