How to dim your lights in the evening for better sleep

Bright light in the two or three hours before bed can delay the evening rise of melatonin, the hormone that helps you feel sleepy at night, and push your sleep later. In a lot of homes the overhead lights, the TV and a laptop are all still on at 9 p.m.

What to change in the living room, bedroom and bathroom

In the living room

Turn the ceiling lights off about three hours before bed, or dim them all the way down if they're on a dimmer. Put a warm, lower-wattage bulb in the floor lamp. If you can, turn it so the light hits the wall behind the sofa instead of your eyes. Switch on a small table lamp next to whoever reads, so nobody needs the overhead back on.

You can leave the TV on. Turn the picture brightness down a few steps. Turn the laptop down to the lowest brightness you can comfortably read.

In the bedroom

Turn the ceiling light off and use a bedside lamp with a warm bulb for getting ready. Charge the phone face down across the room, on a dresser or in a drawer. Put a small piece of tape over any standby light. Blackout curtains will block the streetlight, and an eye mask works if you can't put them up. While you sleep, keep the room as dark as you can.

In the bathroom

The lights over the bathroom mirror are at eye height, a foot or two from your face, for teeth, skincare and contact lenses. In many homes they're among the brightest lights you look at all evening, and they're the ones you switch on if you get up in the night.

At night, leave the mirror lights off and use a plug-in warm night light low on the wall. It's enough to brush your teeth by, and for getting up in the night. If the bathroom has a second, softer light on its own switch, that works too. If skincare needs good light, do it earlier in the evening.

Do room lights affect sleep more than your phone?

In a 2011 study, adults spent the hours before bed in ordinary room light (under 200 lux) instead of dim light. Melatonin started later in nearly every person, and their melatonin stayed high for about 90 fewer minutes overnight ¹.

Normal lights at home are often bright enough to do this. Researchers in Melbourne measured evening light in people's homes and found nearly half were bright enough to cut melatonin by 50% for an average person ².

Screens still have some effect. In a lab study, people who read on a light-emitting tablet for about four hours each evening took longer to fall asleep, had a later melatonin rise and felt less alert the next morning than when they read a printed book ³. That was a long session every night with the screen close to the face, so a few minutes on a dimmed phone matters much less than an evening under bright room lights.

How dim to keep the lights before bed, and for how long

You don't need to measure your lights. Aim for about what one or two low, warm lamps give, starting about three hours before bed, and keep the bedroom as dark as you can while you sleep. Those timings come from a 2022 expert panel ⁴, and the melanopsin guide explains the light levels it recommends.

People also differ a lot. In one study, the light level needed to halve melatonin ranged from about 6 lux in the most sensitive person to 350 lux in the least ⁵.

Where a light is in the room changes how much reaches your eyes. Ceiling lights and lights at eye level matter more than a lamp near the floor, and a lamp whose bulb you can see is brighter at the eye than one bounced off a wall.

Bulb color matters too. Cool white LEDs and bright screens are rich in blue, and at night your body reads that light as daytime, which holds back melatonin. Warm white bulbs send a much weaker signal, so for evening lamps look for "warm white" or 2700K and below. For help picking bulbs, see are LED lights bad for sleep.

A bright kitchen at 7 p.m. matters less than one at 10:30 p.m., as long as you keep things dim after it. Bright light earlier in the evening may also make you less sensitive to light later on. In a small lab study of 12 young women, bright light from 6:30 p.m. to 9 p.m. reduced, but didn't remove, their response to an hour of bright light later that night ⁶.

If you want to go to bed earlier, see the light-timing guide, which also covers morning light.

If you live with other people

If your partner stays up later, agree on one room or one corner that goes dim at a set time. You sit there, and they use the brighter room. In a shared bedroom, try a clip-on book light for them and an eye mask for you.

Parents often get their brightest light of the evening during the kids' bedtime, with the bath under the overhead light and then the kitchen cleanup. Dim the hallway and the kids' room for the routine. If you can, do the bright cleanup before their bedtime instead of after.

If you share a kitchen with roommates, keep your own room dim and spend the last few hours of the evening there. Anyone who needs bright light to study or work late can use a desk lamp aimed at the work, which lights the page without lighting the whole room.