How Light Affects Your Sleep

Published February 14, 2022

• Joanne Chen

Did you know that even the smallest beams of light in your bedroom can become focal points that draw your attention and distract you from sleep? The disappearance of light in the evening tells the brain that it’s time to wind down.

And few people realize that bright-light exposure during the day can improve sleep, since sunlight, especially in the morning, helps to regulate your circadian clock for the day, signaling your brain to wake up.

The bigger the contrast between night and day, the better you sleep. Here’s how to make that happen.

Get outside during the day

We know it’s tough to get outside, especially since everyone is still living through a pandemic.

Maximizing sunlight in the morning helps to optimize sleep at night. Make a plan to take a brief walk or bike ride before you start your day—exercising in the daytime optimizes sleep, too. Or maybe even take your next Zoom call while sitting by a window.

Even if it’s not sunny, step outside anyway: Gray skies still offer about four to five times the light that indoor artificial light does.

Adjust your evening lighting

Bright artificial light in the evening can disrupt sleep, so adjust your lighting. That means dimming overhead lights or switching them off entirely and instead relying on small side-table or nightstand lamps.

It also means limiting sleep-delaying blue light, not only from lamps but also from the biggest culprits: laptops, tablets, and phones.

Bulbs like the Philips Hue, and the SceneSwitch LED let you schedule dimming and eliminate blue light at the same time.

If you read before going to sleep, opt for print. Tablets, laptops, and TVs can make you think you’re less sleepy and cause you to take longer to fall asleep.

If you must use a screen, choose a phone over a tablet, and adjust the screen to its nighttime mode (Night Shift on iPhones, Night Mode on Android phones) to reduce blue-light emission. For some people, blue-light-blocking glasses can be helpful.

Try to limit yourself to less than an hour of reading on your device in the evening. To avoid temptation after your bedtime alarm sounds, make your bedroom a gadget-free zone.

Block light in the bedroom

Go into your room with the lights off and close the door. Do you see any potentially annoying sources of light? Pay attention to smoke detectors, alarm clocks, or anything else that emits even the smallest amount of light. Make a plan to block them.

Blackout stickers, such as LightDims (Black Out Edition), or black electrical tape (use a hole punch to make neat circles) work wonders over indicator lights on cable boxes, USB chargers, and TVs.

Blackout shades or curtains block light coming from your window, and a door sweep can banish that under-door glow. When you’re shopping for blackout curtains and shades, be sure to install them properly so you don’t end up with a “halo” of light around the edges.

You can also tackle all of these distractions by wearing a sleep mask.

This article was edited by Alejandra Matos.

https://www.nytimes.com/wirecutter/blog/how-light-affects-your-sleep/