How Technology Affects Sleep and How to Disconnect Before Bed

The verdict: Screens affect sleep two ways. Bright light, especially blue light, delays melatonin, and interactive content keeps your brain alert. In one set of studies, 1.5 hours of bright screen use was enough to blunt the evening rise in melatonin, and 5 nights in a row shifted the body clock by about 1.5 hours. Stop screens at least an hour before bed, dim them, and keep the phone out of the bedroom.

Technology is part of nearly every hour of the day, and for most of us it is the last thing we look at before sleep. In the National Sleep Foundation's 2011 poll, nine in 10 Americans used some kind of device in the hour before bed.

That habit costs more than a few minutes. The light from a screen tells your brain it is still daytime, and the feed on it gives your mind a reason to stay switched on.

This guide covers what screens actually do to your sleep, what the evidence says about blue light glasses, and seven steps to disconnect before bed that do not depend on willpower. If you are working on your health more broadly, sleep is foundational, and our complete guide to sleep and health covers everything from sleep stages to how rest affects weight loss and mental clarity.

Light that says it's still daytime

Blue light is part of the visible light spectrum. Its wavelengths, roughly 450 to 495 nanometers, are shorter than red and green light. The sun and the sky are its biggest sources, but smartphones, tablets, laptops, LED televisions and energy-efficient bulbs give it off too. Screens emit much smaller amounts than the sky, but you hold them close to your eyes, often at night, which is exactly when your body is least prepared for it.

During the day, blue light is useful. Harvard Health notes that it boosts attention, reaction times and mood, and daytime light keeps your internal clock aligned with the world. At night, the same light works against you.

Here is the mechanism. Light suppresses melatonin, the hormone that signals your body it is time to sleep, and blue light does it more powerfully than other colors. In a Harvard experiment comparing 6.5 hours of blue light with green light of similar brightness, blue light suppressed melatonin for about twice as long and shifted circadian rhythms by twice as much: 3 hours against 1.5 hours.

When melatonin is delayed, your body gets a weaker signal that it is time to sleep. Your circadian rhythm, the internal clock that decides when you feel alert or sleepy, drifts later. You fall asleep later, sleep less deeply, and wake up tired.

Younger people may be hit hardest. A 2024 review in Chronobiology in Medicine of studies in high school and college students concluded that blue light exposure, especially before bedtime, can disrupt circadian rhythms and melatonin and is tied to worse sleep quality and duration, with knock-on effects on mood, memory and grades.

The Sleep Health Foundation summarizes studies of bright tablets and laptops used for up to 5 hours before bed: 1 hour did not affect the natural evening rise in melatonin, but 1.5 hours did. After 1.5 hours, people felt less sleepy and their brainwaves showed more alertness.

A later body clock, night after night

One late night on your phone costs you some sleep. The bigger problem is repetition. Repeated use of a bright screen over 5 days can delay the body clock by about 1.5 hours, according to the Sleep Health Foundation. You want to go to bed later and sleep in longer, which is a real problem when your alarm is set for work or school.

Long-term nighttime screen use can add up to chronic sleep disruption, which brings fatigue and may be linked with mood changes. Light at night and circadian disruption have been associated with diabetes, heart disease and obesity, though Harvard Health is careful to say that is not proof that nighttime light causes them, and the specific role of personal devices is still being studied.

Extended screen use can also cause digital eye strain, sometimes called computer vision syndrome. It comes mostly from long periods of focusing on a screen, blinking less and glare, rather than from blue light itself. Symptoms include dry eyes, headaches, blurred vision and eye discomfort.

Light is only half the story. Many of us use our phones, laptops and tablets before bed to read news, answer messages and scroll social feeds. That content is stimulating by design. Notifications and updates can cause anxiety, and the urge to check one more thing keeps your mind working when it should be winding down.

The 2011 poll found the kind of device matters. In the National Sleep Foundation data, the more interactive devices people used in the hour before bed (computers, cell phones, video games), the more likely they were to report trouble falling asleep and unrefreshing sleep. Passive ones like TV and music players showed no such link. Cell phones were the norm for younger people: 72% of teens and 67% of young adults used one in that hour, compared with 36% of adults 30 to 45 and 16% of those 46 to 64.

Disconnecting is hard for a reason. Many people are connected all day for work, family and entertainment, and putting the phone down feels like being unreachable. That constant connectivity makes it harder to mentally wind down, which can delay sleep or reduce its quality. The steps below are built around that reality.

Seven steps to wind down

None of these require throwing your phone in a drawer for good. Start with one or two, and add the rest as they stick.

Set a screen curfew

Stop at least an hour before bed

Pick a time to stop using screens and treat it like an appointment. At least an hour before bed is a realistic start, since the Sleep Health Foundation data showed the melatonin effect kicking in at 1.5 hours of bright screen use.

If you can go further, Harvard Health suggests avoiding bright screens beginning 2 to 3 hours before bed. Set a recurring alarm on your phone as the cue, which is the one notification worth keeping.

Turn on night mode & dim the screen

Less light if you do use it

Use a blue light filter. Most smartphones and tablets have a built-in night mode that shifts the screen toward warmer colors in the evening.
Lower the brightness. The Sleep Health Foundation's first tip is to dim the screen as much as possible for evening use.
Schedule it. Settings or apps that gradually warm your screen's color as bedtime gets closer do the job without you remembering.
Dim the room too. Harvard Health notes that even dim light can affect melatonin, and it suggests dim red lights for night lights.

Night mode reduces the light. It does nothing about the content, which is why it is a step, not the whole plan.

Swap interactive screens for passive ones

A book instead of the feed

If you are going to use a device late, pick one that asks less of you. The Sleep Health Foundation recommends switching interactive devices, like a phone, to passive ones, like an e-reader, in the evening. Music, an audiobook or a podcast work the same way.

The difference showed up clearly in the 2011 poll: interactive devices were linked with sleep complaints, and passive ones were not. Messages and feeds pull you back in. A chapter of a book ends.

Charge your phone outside the bedroom

Out of arm's reach

Setting boundaries for technology is easier when the device is not within arm's reach. Plug your phone in somewhere else, the kitchen or a hallway, and use a basic alarm clock if your phone doubles as one.

This removes the 2 a.m. check, the first-thing-in-the-morning scroll, and the light of incoming notifications. It also makes the bedroom a place for sleep, which sleep experts recommend.

Build a tech-free bedtime routine

Give your evening a last hour

Finding something to do instead of screens is essential, or the phone wins by default. Set aside the last stretch of the evening for technology-free activities:

Read a book. A paper book is a good way to wind down and can help you fall asleep sooner.
Listen to music or a podcast. It is relaxing and asks nothing of your eyes.
Practice yoga or meditation. Yoga and meditation can be very relaxing. If you are new to it, a guided sleep meditation is an easy way in.
Take a warm bath or shower. It helps you relax and gives your body a clear signal that the day is ending.

Do the same things in the same order each night. Over time, the routine itself trains your mind and body to associate that hour with sleep.

Use screen time tools

Let the phone set the limit

Your phone can help you use it less. Built-in screen time settings track how long you spend on each app, can lock distracting apps after a set time, and can silence notifications overnight with a sleep or do not disturb mode.

Set them up once, when you are not tired. At 11 p.m., a default is much easier to follow than a decision.

Keep a consistent sleep schedule

Same time to bed, same time up

Going to bed and waking up at the same time every day helps regulate your circadian rhythm. It is also the best defense against the body clock drift that repeated late screen use causes.

Weekends count. Sleeping in by 2 hours on Saturday and Sunday shifts your clock the same way a late night on your phone does, and Monday morning pays for it.

Movement, caffeine, alcohol & dinner

Disconnecting from technology is one lever. A few others work alongside it.

Stay active during the day. Regular exercise and physical activity can improve your sleep quality and help you fall asleep faster, and daytime light outdoors helps anchor your body clock.

Limit caffeine well before bed. Caffeine is a stimulant, and its effect lasts longer than most people think. In a study in the Journal of Clinical Sleep Medicine, a 400 mg dose of caffeine disrupted sleep even when it was taken 6 hours before bedtime. That is about two to three 12-ounce cups of coffee, per the FDA. The authors' advice: no substantial caffeine for at least 6 hours before bed.

Go easy on alcohol at night. Alcohol is not a stimulant, it is a sedative, which is why it can feel like it helps. A review of the sleep studies found that alcohol at every dose helps you fall asleep faster but increases sleep disruption in the second half of the night, and moderate to high doses cut REM sleep. You fall asleep quicker and sleep worse.

Eat well to support sleep. Heavy, rich meals close to bedtime can cause discomfort and disrupt rest, while going to bed hungry can interfere with sleep too. Our guide to how diet affects sleep goes deeper.

Mixed results, so far

Amber-tinted or blue light blocking glasses filter some of the blue light reaching your eyes, and they are often sold as a sleep fix. The evidence is mixed.

A 2023 Cochrane review of 17 trials found the effect on sleep quality could not be determined: three of six sleep studies found an improvement, three found no difference, and the evidence was very low certainty. On the other side, a 2025 trial in 39 Japanese schoolboys aged 10 to 12 found that glasses blocking 40% of blue light, worn for 3 hours before bed, moved bedtime and sleep onset about 6 minutes earlier and reduced daytime irritability, though they did not change melatonin levels.

So glasses may help some people, a little. They cost more than night mode, which is free, and neither fixes a feed that keeps you scrolling.

Where good intentions go wrong

Trusting night mode to do everything. It dims the color, not the content. An hour of messages in amber is still an hour of messages.
Falling asleep to the TV. The Sleep Health Foundation notes that relying on a TV to fall asleep can make it harder to fall back to sleep when you wake in the night.
Using the phone as an alarm clock. It puts the device on your nightstand, where the last check and the first check both happen.
Doing work email in bed. Work content is the most stimulating kind, and it teaches your brain that bed is a place to think.
Catching up on sleep with a weekend lie-in. It shifts your body clock later and makes Sunday night harder.

Better sleep, calmer evenings

Disconnecting from technology before bed is one of the simplest changes you can make for a good night's sleep. Here is what it buys you.

Better sleep quality. Researchers define sleep quality by how long you take to fall asleep, how long and how efficiently you sleep, and how much you wake after sleep onset, and they list television and device use among its environmental influences. A calmer, darker last hour supports all four.
Less stress and anxiety. Being constantly connected can cause stress and anxiety. Stepping away before bed lets you relax and shrinks the space where worries grow.
Better mental and physical health. Enough sleep is crucial for both. Poor sleep quality is tied to fatigue, irritability, slower responses and more reliance on caffeine the next day.

Dinner done before the wind-down

What you eat plays a role in how well you sleep, and when you eat matters too. The hard part is usually not knowing that. It is getting a balanced dinner on the table early enough when the evening is already short, so it doesn't push into the hour you meant to protect.

Having balanced, portioned meals ready to heat makes that easier. Our Build A Meal Plan lets you pick meals one by one, and our Weight Loss Meal Plan comes portion-controlled and calorie-controlled, from $89.95 for 10 meals. Each meal heats in a few minutes, there is no subscription, and meal plan orders ship free to the contiguous 48 states. Less time in the kitchen at 8 p.m. means more time to wind down before bed.

Quick answers

How does blue light from screens affect sleep?

Blue light from electronic devices suppresses melatonin, the hormone that regulates your sleep-wake cycle. That makes it harder to fall asleep and can reduce sleep quality. Studies summarized by the Sleep Health Foundation found that 1.5 hours of bright screen use blunted the evening melatonin rise, and 5 nights in a row delayed the body clock by about 1.5 hours.

How long before bed should you stop using technology?

At least an hour before bed is a realistic minimum, since studies found the melatonin effect after about 1.5 hours of bright screen use. Harvard Health suggests avoiding bright screens 2 to 3 hours before bed if you can. A tech-free routine for the full last hour is a good place to start.

Do blue light blocking glasses help with sleep?

The evidence is mixed. A 2023 Cochrane review of 17 trials could not determine an effect on sleep quality, with half the sleep studies finding a benefit and half finding none. A 2025 trial in schoolboys found glasses moved sleep onset about 6 minutes earlier. Night mode and a screen curfew are cheaper places to start.

Why is it hard to disconnect from technology before bed?

Smartphones create a habit of being always on. Notifications, social media and the pressure to stay available trigger anxiety and mental stimulation that make it hard to relax. Interactive devices are the hardest to put down, and in a national poll they were the ones most linked with trouble falling asleep.

What are the best alternatives to screen time before bed?

Effective alternatives include reading a paper book, practicing yoga or meditation, taking a warm bath, listening to calming music or podcasts, and light stretching. These activities help your body transition into a relaxed state. Doing them in the same order each night turns them into a cue for sleep.

Is watching TV before bed as bad as using a phone?

Probably not. TV is a passive device, and in the 2011 National Sleep Foundation poll it was interactive devices like phones and computers that were linked with trouble falling asleep. The Sleep Health Foundation does caution against needing the TV on to fall asleep, since it can make waking in the night harder.

Start with one habit tonight

Technology is woven into nearly every part of our lives, but that doesn't mean it should follow us to bed. The light from screens, the mental stimulation of the content, and the pull of constant connectivity all work against the rest your body needs.

Small changes make a real difference. Start with one habit: put your phone in another room an hour before bed, swap scrolling for reading, or turn on night mode in the evening. Over time, these adjustments train your brain to recognize when it is time to wind down.

For a deeper look at why sleep matters for everything from weight management to mental clarity, explore our complete guide to sleep and health.

This article is for informational and educational purposes only and is not intended as medical advice. Please talk with a qualified healthcare professional about any questions on sleep or health concerns.