Blue light can affect sleep, going by a 2015 study in PNAS from Brigham and Women's Hospital in Boston. As I read it, evening light from an iPad held back melatonin, the hormone that helps you fall asleep, and pushed the body clock later. A 2025 Norwegian study of 45,202 students adds a twist: the light itself may matter less than the time screens take from sleep.
Blue light is the short-wavelength part of the light we can see, and the iPad in the Boston study peaked at 452 nanometres, in the blue range. I'm Michael Ruhr, and I co-own Merit Home Furniture, which has four stores on Vancouver Island and takes online orders through our Duncan store. I sell beds, mattresses and bedroom furniture. I don't treat sleep problems, so every health point that follows comes from a named source, mostly HealthLink BC, the Canadian Paediatric Society and peer-reviewed studies.
Blue light late in the evening probably nudges sleep later. Daylight in the morning, on the other hand, is something HealthLink BC suggests getting more of.
How does blue light affect sleep? Melatonin and the body clock
Going by the 2015 PNAS study in the table below, blue light affects sleep mainly through the body clock. HealthLink BC explains that light and dark affect how your body makes melatonin, a hormone that helps you fall asleep and stay asleep. Most melatonin is made at night. During the day, light tells the body to make less of it.
Screens bring some of that daytime signal into the evening. One widely cited study on this came from Brigham and Women's Hospital and Harvard Medical School, published in PNAS in 2015. Anne-Marie Chang and colleagues had 12 healthy young adults read for about 4 hours before bed, five evenings in a row, in very dim room light. Each person did this once with an iPad and once with printed books, in random order.
| What was measured | iPad evenings, against printed books |
|---|---|
| Evening melatonin | Suppressed by about 55% on the fifth night; no suppression with the book |
| Melatonin onset | More than 1.5 hours later the next evening |
| Time to fall asleep | Nearly 10 minutes longer, about 26 minutes against 16 |
| REM sleep | About 109 minutes against 121 |
| The next morning | Sleepier, and it took hours longer to feel fully alert |
| Light at the eye | 31.73 lux from the iPad, 0.91 lux reflected off the printed page |
So on this evidence, blue light disrupts sleep mainly through timing. Melatonin rises later, sleep starts later, and the morning feels groggier. Two cautions apply. Twelve people is a small group, and 4 hours of reading in a nearly dark room is likely more screen light than most evenings hold.
Does blue light actually affect sleep as much as screen time does?
Blue light is only one of four ways screens are thought to affect sleep. A 2025 study in Frontiers in Psychiatry lists them. Screen use can replace sleep outright, its light can hold back melatonin, the activity can keep the brain alert, and notifications can wake people once they've dropped off.
That study, led by Gunnhild Johnsen Hjetland in Norway, surveyed 45,202 students aged 18 to 28. Each extra hour of screen use after going to bed was linked to 59% higher odds of insomnia symptoms and 24 minutes less sleep. The link was the same for social media as for films, music or gaming. The authors read this as screen time pushing sleep aside. They also say a one-time survey can't prove cause, since poor sleepers may reach for a phone to pass the time.
A 2024 theoretical review in Sleep Medicine Reviews, by Serena Bauducco and colleagues, takes that second idea seriously. It proposes that screens before bed may work as a time filler, or a way to settle emotions, for people already struggling to drop off. The Norwegian team sums up that review as finding light and arousal have shown minimal effects on sleep in experimental studies.
What devices emit the most blue light, and does the TV count?
I couldn't find a Canadian health authority that ranks devices by blue light. HealthLink BC's page on sleep problems names the TV, computer, smartphone and tablet together, and suggests not using any of them in bed. Its insomnia advice adds a plain line: "Don't watch TV in bed."
A phone held close to the face sits nearer the eyes than a TV across the room. That's geometry, not a study. The TV still counts as evening light and as screen time, and both are what the advice is aimed at.
Binge-watching and sleep
Binge-watching has its own research. In a 2017 study in the Journal of Clinical Sleep Medicine, Exelmans and Van den Bulck surveyed 423 adults aged 18 to 25, and 80.6% called themselves binge viewers. More frequent binge-watching was linked to poorer sleep quality, more fatigue and more insomnia symptoms. Ordinary TV viewing was not. The link ran through an alert, busy mind at bedtime, which the authors call cognitive pre-sleep arousal.
Blue light glasses and night mode: what the sleep trials found
Blue light glasses and night mode both aim to take the blue out of the evening. For sleep, neither has strong trial evidence behind it yet.
Blue light glasses
A 2023 Cochrane review, led by Sumeer Singh at the University of Melbourne, gathered 17 randomised trials of blue-light filtering lenses in adults. Six of them, with 148 people in all, looked at sleep. Three found better sleep scores with the filtering lenses, and three found no difference. The reviewers rated that evidence very low certainty and wrote that they do not know whether the lenses help sleep.
Night Shift and other night modes
Apple's Night Shift is meant to cut a phone's short-wavelength light in the evening. A 2021 study in Sleep Health, by Kara Duraccio and colleagues, split 167 students aged 18 to 24 into three groups for seven nights. One group used an iPhone with Night Shift on, one with it off, and one used no phone in the hour before bed. Wrist trackers found no difference in sleep between the three groups.
One detail from the Duraccio study stands out. Among students who usually slept more than 6.8 hours, the no-phone group slept most efficiently. The Cochrane reviewers also found the lenses may not ease eye strain from computer use, so sore or tired eyes are a question for an optometrist.
Does blue light help you sleep? Daylight, mornings and the body clock
Whether blue light helps sleep depends on timing, and the evidence is thin. A 2022 systematic review in Frontiers in Physiology, by Silvani and colleagues in Switzerland, summed up the research. In slightly more than two thirds of the studies measuring alertness, it rose with blue light. The authors call for more research on whether blue light can improve sleep. Alertness is welcome in the morning and less so near bedtime.
Daylight is the light HealthLink BC recommends. Its insomnia page suggests "plenty of sunlight in the outdoors." It names the morning and late afternoon in particular. Its page for older adults says time in sunlight helps to reset the body's sleep and wake cycles. On grey Island mornings in November, while you're adjusting to the end of daylight saving, a walk outside or a coffee by the window is the easy habit to drop.
Light boxes are a different matter. HealthLink BC describes light therapy with a bright 10,000 lux light box for 30 to 45 minutes a day, and says to ask your doctor for the schedule. Timing changes the effect. The same page uses morning light for night owls trying to wake up early and evening light for early birds.
Why do seniors wake up at 3:00 am?
HealthLink BC says sleep patterns naturally change with age. Compared with younger people, older adults take longer to fall asleep, sleep less soundly and wake more often in the night. Its body clock page describes early birds who fall asleep at 8 p.m. or earlier and wake between 3 a.m. and 5 a.m.
HealthLink BC adds that these normal changes don't mean the sleep is enough. Health problems, medicines and stress from big life changes can all wear sleep down. It suggests older adults who have trouble sleeping talk to their doctor, and waking at 3 every night is worth raising.
Screens, children and sleep: what Canadian guidelines say
Children's screens come with firmer advice than adults'. The Canadian Paediatric Society's statement on digital media for school-aged children and teens dates from 2019 and was reaffirmed in July 2025. It says screens in the bedroom interfere with sleep duration and quality. It asks doctors to remind parents and teens to avoid screens at least 1 hour before bedtime and to discourage recreational screen use in bedrooms.
The statement also cites a 2014 Canadian survey of students with cellphones. Of those students, 39% slept with their phones, from 20% in Grade 4 to 51% in Grade 11.
| Age | Screen and sleep guidance |
|---|---|
| Under 2 | Screen use not recommended, except video chats with caring adults (Canadian Paediatric Society) |
| 2 to 5 | About an hour or less a day; all screens out of the bedroom, none for at least 1 hour before bed (Canadian Paediatric Society) |
| 5 to 13 | No more than 2 hours per day of recreational screen time; 9 to 11 hours of uninterrupted sleep (CSEP) |
| 14 to 17 | The same 2-hour screen limit; 8 to 10 hours of sleep (CSEP) |
| 18 to 64 | No more than 3 hours of recreational screen time; 7 to 9 hours of good-quality sleep (CSEP) |
CSEP is the Canadian Society for Exercise Physiology, which publishes the 24-Hour Movement Guidelines. HealthLink BC's advice for teens runs the same way. It suggests taking the TV, computer, phone and video games out of a teen's room.
A bedroom without a TV: where the charger, the books and the lamp go
A bedroom without screens is mostly about habit. Merit sells the furniture, not the habit, and a dresser can only make the habit easier to keep. I can't promise it will change anyone's sleep, but I can suggest where things go.
The phone charger is the first thing I'd move. On the nightstand, the phone is in reach all night. On a dresser across the room, or a shelf in the hall, it takes getting up to scroll. That fits HealthLink BC's suggestion not to use a phone in bed at all.
The TV can stay in the living room. HealthLink BC's insomnia page suggests reserving the bed for sleep and sex. It also says a bit of light reading may help you fall asleep, so the nightstand can hold a lamp, a book and a glass of water. Merit's guide to matching a nightstand to the height of your mattress covers the fit. The same HealthLink BC page suggests a pillow and mattress that are comfortable for you, and our notes on pillow height by sleep position can help there.
Of the 48 nightstands on Merit's site, 37 list Duncan. Here are a few Merit pieces that suit a screen-free setup, with prices as listed on November 1, 2026, before applicable taxes.
| Piece | Size, price and store |
|---|---|
| Mako Polo 48-inch 6-drawer dresser | 48 W x 30 H x 18 D inches, solid pine, $799.00; Duncan and Port Alberni |
| Mako Youth 48-inch 6-drawer dresser | 48 W x 30 H x 18 D inches, $799.00; Duncan |
| LH Home West nightstand | One drawer over an open niche of 18 x 17 x 4 inches, $349.00; on display at our Duncan store |
| Mako Youth 2-drawer nightstand | 22 W x 21.5 H x 18 D inches, $349.00; Duncan |
| Mako Youth bookcase headboard | 45.5 inches high, 8 deep; twin $599.00, queen $649.00; Duncan and Port Alberni |
The Youth bookcase headboard is the one I'd point to in a child's room, since the shelf behind the pillow holds books rather than a tablet. Mako is what the Province of BC calls a furniture producer in Surrey, and a Mako order takes 8 to 10 weeks before it's ready for pickup or delivery. A separate guide covers where Mako builds and what wood it uses. Our notes on choosing a dresser by height and drawer count help with the rest of the room.
When poor sleep needs a doctor, not a darker bedroom
A screen habit is one possible cause of poor sleep among many. HealthLink BC notes that sleep problems may be a symptom of a medical or mental health problem. Treating a long-term sleep problem without looking for the cause may hide the real reason. These are the signs its sleep pages list.
| HealthLink BC says | When |
|---|---|
| Call 9-1-1 | Someone is thinking seriously of attempting suicide; the sleep problems checker treats this as an emergency and also lists Talk Suicide Canada at 1-833-456-4566 |
| Talk to a doctor | Daytime sleepiness gets in the way of normal things; don't drive or use machinery while drowsy |
| Talk to a doctor | Choking or gasping for breath in sleep, loud snoring or waking unrefreshed, which can be signs of sleep apnea |
| Call a doctor | During home care, feeling very tired or struggling to function in the day, or symptoms coming more often or more severely |
| Talk to a doctor | A child often has trouble getting to sleep or staying asleep |
| Talk to a doctor | Sleep hasn't improved after more than 2 weeks of home treatment, or an older adult has ongoing trouble sleeping |
For anything in between, 8-1-1 reaches HealthLink BC, where nurses answer 24 hours a day, 7 days a week. Callers who are deaf or hard of hearing can dial 7-1-1 instead.
The research Merit has drawn on here has limits too. The studies above are small, run on young adults, or are surveys that can't show cause. That's why every finding above is hedged, and why none of it is a diagnosis.
Where the blue light and sleep facts come from
- PNAS, 2015: Chang, Aeschbach, Duffy and Czeisler, evening use of light-emitting eReaders and sleep, 12 adults (PMC 4313820), checked November 2026.
- Frontiers in Psychiatry, 2025: Hjetland and colleagues, screen use in bed and sleep in 45,202 Norwegian students, checked November 2026.
- Sleep Medicine Reviews, 2024: Bauducco and colleagues, a bidirectional model of sleep and technology use (PubMed 38657359), checked November 2026.
- Journal of Clinical Sleep Medicine, 2017: Exelmans and Van den Bulck, binge viewing, sleep and pre-sleep arousal (PubMed 28728618), checked November 2026.
- Cochrane Database of Systematic Reviews, 2023: Singh and colleagues, blue-light filtering spectacle lenses for visual performance, sleep and macular health (PubMed 37593770), checked November 2026.
- Sleep Health, 2021: Duraccio and colleagues, iPhone Night Shift and sleep in 167 emerging adults (PubMed 33867308), checked November 2026.
- Frontiers in Physiology, 2022: Silvani, Werder and Perret, systematic review of blue light, sleep, performance and wellbeing (PubMed 36051910), checked November 2026.
- Canadian Paediatric Society, Digital media: Promoting healthy screen use in school-aged children and adolescents (reaffirmed July 4, 2025), checked November 2026.
- Canadian Paediatric Society, Caring for Kids: Screen use and young children (updated March 2025), checked November 2026.
- Canadian Society for Exercise Physiology, 24-Hour Movement Guidelines for Children and Youth, 5 to 17 years, checked November 2026.
- Canadian Society for Exercise Physiology, 24-Hour Movement Guidelines for Adults, 18 to 64 years, checked November 2026.
- HealthLink BC, Sleep and Your Body Clock, checked November 2026.
- HealthLink BC, Insomnia: Improving Your Sleep, checked November 2026.
- HealthLink BC, Coping With Changing Sleep Patterns as You Get Older, checked November 2026.
- HealthLink BC, Sleep Problems, Age 12 and Older (with its symptom checker and crisis lines), checked November 2026.
- HealthLink BC, Sleep: Helping Your Children, and Yourself, Sleep Well, checked November 2026.
- HealthLink BC, 8-1-1 services, checked November 2026.
- Merit Home Furniture's live nightstand, dresser and headboard listings, sizes, prices and store lists, read November 1, 2026, and the owners' delivery and lead-time terms.
Asking about bedroom furniture at our Duncan store
You'll find Merit in Duncan at 107 Ingram St, open 9 to 5 from Monday through Saturday. Most pieces in the store are display models, so a call ahead tells you which dressers and nightstands are set up. Delivery from our Duncan store across the Island costs $150 with setup and assembly, and picking up at the store costs nothing. We can take old furniture away when we deliver, usually $25 to $50 a piece.
The rest of our sleep and mattress guides for Island homes cover beds, sizes and feel. The pieces above sit with the nightstands we list, our dressers and furniture for kids' rooms.