Start outside
Streetlights, early sunrise and security lights usually call for window coverage, better curtain fit or a sleep mask.
Bedroom guide
How dark should a bedroom be?
Dark enough to feel comfortable and reduce unwanted light, while still keeping nighttime movement safe if you need it.
A useful target
Reduce the light that interrupts your room—not every trace of light at any cost.
The CDC recommends a bedroom that is quiet, relaxing and comfortably cool, and its sleep guidance includes reducing light in the sleep environment.[1] Research reviews also support paying attention to timing and the amount of light, but do not define one perfect bedroom darkness level for everyone.[2]
Then check indoors
Chargers, clocks, LEDs and hallway spill may be easier to switch off, move or cover than to shop around.
Keep safety in view
If you need to get up at night, use a low, dim path light rather than navigating in a way that feels unsafe.
A quick room audit
Find the brightest source after lights-out.
Stand in the room with the main lights off. Notice what catches your eye first, then address that one source before buying anything else. This makes product choices more relevant and less wasteful.
Read the blackout-curtain guide →References
Sources cited in this article
- Centers for Disease Control and Prevention. About Sleep. Accessed 19 September 2026. Read the guidance.
- Dautovich ND, Schreiber DR, Imel JL, et al. A systematic review of the amount and timing of light in association with objective and subjective sleep outcomes in community-dwelling adults. Sleep Health. 2019;5(1):31–48. doi: 10.1016/j.sleh.2018.09.006. PMID: 30670164.