Assessment
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Quick Win
The glow from lamps and streetlights can act like the sun, affecting your circadian rhythm and alerting you to wake up.
Try This Today
- Block light from the windows with room-darkening shades or blackout curtains and turn off hallway lights, which can shine through the gap under the door.
- Wear an eye mask. The mask not only blocks out light, it may signal to your brain that it’s time to sleep.
- If you use a night-light, try a red-spectrum bulb. The red is less likely than blue or bright white light to interrupt the body’s natural rhythms.
Why
Bright light hampers your body’s release of melatonin, a hormone that helps bring on sleep. High amounts of outdoor artificial light at night were associated with a small decline in deep sleep in a study published in BMC Public Health in 2026. For the study, researchers analyzed sleep tracker records from 4,690 people — about half of whom were ages 45 or older — and used satellite data to match their estimated city-level exposure to outdoor light at night with their sleep patterns.
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