For something we are meant to spend a third of our lives doing, plenty of us aren’t very good about sleep. Whether we underdo it, overdo it or simply don’t do it effectively, as many as a third of adults struggle with shut-eye, according to the Centres of Disease Control and Prevention in the US.
If you've tried all the textbook solutions – avoiding caffeine, setting a bedtime and wake-up routine, and exercising regularly – to no avail, then perhaps, in light of World Sleep Day, which falls on Friday, aligning your home lighting design with your circadian rhythm is the solution you've been seeking for better rest.
"We respond very much to light," says Dr Neil Stanley, who is a sleep expert and author of How to Sleep Well. "We evolved on this planet, where the sun comes up and goes down, meaning our circadian rhythm exists whether we like it or not."
More commonly referred to as the internal body clock, our circadian rhythm tells us when to wake up, unwind, release hormones and so on, and it is controlled by exposure to light. However, humankind's relationship with light has changed dramatically over the past 200 years, primarily owing to our ability to manipulate it.
Given the new research on how crucial our circadian rhythm is to our overall health, let alone our sleep, journalist Linda Geddes centred her groundbreaking 2019 book, Chasing the Sun, on the connection between sleep and light.
She set out to do some testing of her own. Working with the University of Surrey, Geddes set herself a six-week challenge to maximise her exposure to natural light in the day and limit or avoid all artificial light exposure after 6pm.
"I definitely was sleepy earlier in the evenings. I wanted to go to bed at sort of 9pm or 10pm rather than 11pm or midnight," she told Dr Rangan Chatterjee on his podcast Feel Better, Live More.
Once a week, a reading was taken of Geddes's melatonin levels. A crucial hormone that works within our 24-hour cycles, it signals to the body that sleep is approaching. The release of melatonin is blocked by an exposure to light and is encouraged by darkness.
“What we found is that I started secreting melatonin about two hours earlier than normal. My body was saying: ‘It’s night-time,’” said Geddes.
Harnessing the power of light and dark doesn't have to be a dramatic lifestyle change; it could start with simple updates to your interiors.
Jonathan Ashmore, founder of Anarchitect, and Alina Bokhari, founder of the eponymous interior design company, share their expert home lighting tips that could promote a better night's sleep.
Chase the sun in the layout
If Geddes’s book title is anything to go by, it’s that we should all be following the path paved by the sun. It’s something Ashmore is also passionate about. “It’s essential to understand the orientation of the property and the sun path, and how natural light enters your home. Then you can rearrange furniture or uses for each space to where you might be at various times of the day.”
For spaces where you spend the majority of the time in the evening – your living room and bedroom – aim to face west, towards the direction of sunset. Being in line with the sun's natural cycle can keep your circadian rhythm in tune and let you know when to unwind.
Seek darkness by design
Lighting in any given space is not simply about the light source itself, but how it interacts with the environment. Ashmore says: "Brighter surfaces and lighter colours help to increase the light reflected back into an interior space." This is why, while bright colours might be ideal for the office, muted hues are better for the bedroom. Bokhari advises "dark moody colours, soft drapey fabrics and blackouts for the windows, which can work a charm for promoting deep sleep".
In her own home, she says: “I had the walls painted a green-grey-undertoned midnight blue – almost like the colour of the deepest part of the ocean – a plush rug underfoot in tones of charcoal grey, deep burgundy and mustard, and deep grey velvet curtains that fall dramatically to the floor.”
Match lights to activities
"A room's purpose dictates what role lighting should play in the overall design, be it functional, decorative or to create ambience," says Bokhari. When it comes to the bedroom, she recommends ditching the overhead lighting, a main takeaway from Geddes's experiment, too.
Make soft lighting sources such as bedside tables and candles your go-to. Elsewhere, install a low-level lighting option in every room, such as spotlights, floor lamps and desk lamps. By evening, “only use these key task lights for specific tasks where bright light is required”, says Ashmore.
Avoiding all-consuming light after sunset should ensure your circadian rhythm is not confused into staying alert.
Set the tone with warm hues
Unless you intend on living by candlelight, artificial light is generally unavoidable. But making sure your light sources are complementary in tone to the sun’s natural cycle can make all the difference.
"For artificial light, check the [white] colour temperature of the lamps you are using and consider using a dimming light control or reducing the colour temperatures to suit a more ambient light level, such as 2,700K in the evenings," says Ashmore.
Opt for warm, orange-toned lighting for bedroom and relaxation spaces, and shop for light bulbs with a low lux (measure of illuminance) level.
Design a ‘night mode’ routine
There’s no way to avoid that “any light at night is essentially a symbol to be awake”, says Dr Stanley. “If we replace the sunlight with some other device, like a screen or a Kindle or anything with a blue light, that still will have an effect on our sleep.”
We all know this, but it's worth reminding ourselves when redesigning a space for better sleep: keeping blue-light emitting technology out of the room is essential.
Because steering clear of technology isn't always realistic, Geddes found employing each gadget's night mode made a noteworthy difference.
However, if you are determined to elevate the quality of your shut-eye this World Sleep Day, take these measures in your bedroom: fill a bookshelf with paperback novels over digital readers, buy an alarm clock to avoid sharing a bed with a phone, and try audio mediums rather than being glued to Netflix in bed.