The Truth About Screen Time and Sleep

Tracey Mudge
May 27
5 min read

In our digital world, screens are everywhere! From the phones in our hands to the laptops on our desks and the TVs in our living rooms. They help us stay connected, entertained, and informed. But when the day winds down and it's time to sleep, these same screens can become one of the biggest obstacles standing between us and a restful night.

The link between screen time and sleep quality is more than just a hunch or a trending topic - it’s a well-documented, scientifically backed concern. Whether it’s endlessly scrolling through social media in bed or answering late-night work emails, our screen habits directly affect the way we sleep, how long we sleep, and how rested we feel the next day.

In this blog, we’ll explore the science behind screen exposure and sleep disruption, real-life ways this shows up, and practical, realistic suggestions for building healthier digital boundaries.

The Science: Why Screen Time Affects Sleep

At the heart of the issue is something called blue light - a high-energy, short-wavelength light that’s naturally present in sunlight. During the day, blue light helps regulate your circadian rhythm by keeping you alert and signalling that it’s time to be awake. But at night, artificial blue light from screens can trick your brain into thinking it’s still daytime, delaying the natural release of melatonin (the hormone responsible for preparing your body for sleep).

When melatonin release is delayed, so is sleep onset. This not only makes it harder to fall asleep, but also impacts your sleep quality throughout the night.

How exposure to blue light affects the brain and body

Research at a glance:

A Harvard study found that exposure to blue light in the evening suppresses melatonin twice as long as other light wavelengths and shifts circadian rhythms by up to 3 hours.
A 2017 meta-analysis in Chronobiology International concluded that even 30–60 minutes of screen exposure before bed can significantly reduce total sleep time and increase sleep latency (the time it takes to fall asleep).
Research published in JAMA Paediatrics found that increased screen time in children and teens was associated with delayed bedtime, reduced sleep duration, and poorer sleep efficiency.

The effects are not limited to melatonin. Screen engagement (especially with social media or emotionally stimulating content) also raises cortisol and dopamine levels, increasing alertness and mental activity just when your body is trying to power down.

Real-Life Examples: How It Plays Out in Everyday Life

Consider Lisa, a busy working mum who uses her evenings to catch up on personal messages and scroll through Instagram. She gets into bed at 10:30 p.m., but stays on her phone until close to midnight. She’s tired the next morning and hits snooze several times. By mid-afternoon, she’s foggy, craving caffeine, and frustrated that she never feels fully rested (even though she’s “in bed” for eight hours).

Or Mark, a student who watches YouTube and streams shows late into the night. He often tells himself, “just one more episode,” but ends up falling asleep well after midnight. He finds it hard to wake for classes, struggles to concentrate, and has noticed he’s more irritable lately.

These aren’t just stories. They’re common experiences. In fact, the Sleep Foundation reports that over 70% of adults and 90% of teens in the U.S. use electronic devices within an hour of bedtime - a habit that’s quietly undermining sleep health around the world.

Screen Time and Teens: A Unique Risk

Teens are particularly vulnerable to the effects of nighttime screen use. Not only are their brains still developing, but their natural circadian rhythms already shift later during adolescence (meaning they’re biologically inclined to stay up later). Add late-night TikTok scrolling, group chats, and gaming to the mix, and it becomes even harder for them to get the 8–10 hours of sleep they actually need.

A 2019 study published in Nature and Science of Sleep found that teenagers who used screens for more than two hours in the evening reported significantly more difficulty falling asleep, shorter sleep duration, and higher rates of daytime fatigue compared to peers with less screen exposure.

What’s more, these patterns can have long-term effects. Poor sleep in teens is linked to lower academic performance, increased anxiety and depression, and a higher risk of developing chronic sleep disorders later in life.

What About Adults Who “Relax” With Screens?

Many adults use TV or phone time as a way to unwind after a busy day. It feels comforting, passive, and familiar. But, neurologically, it’s anything but passive.

The emotional content of what you consume matters. Watching a high-drama series, reading heated comments, or checking stressful work messages activates your limbic system - the part of your brain responsible for processing emotion and threat. That can trigger subtle stress responses, including elevated heart rate and cortisol levels, making it harder to slide into a restful state.

Even relaxing content can be stimulating to the brain when consumed through backlit devices. The constant scroll of new content, likes, and comments keeps the brain primed for activity rather than rest.

Sleep and Screens: Practical Tips That Actually Work

You don’t need to ban screens completely to sleep better, but you do need to be intentional. Here are evidence-based ways to protect your sleep without feeling like you’re giving up everything you enjoy:

1. Set a Digital Wind-Down Time

Aim to stop using phones, tablets, or computers at least 60 minutes before bed. This gives your body time to naturally increase melatonin levels and transition into sleep mode.

2. Use Night Mode or Blue Light Filters

Most modern devices have night mode settings or downloadable blue light filters that reduce exposure to stimulating wavelengths. While not perfect, they’re better than nothing (especially if screen use is unavoidable).

3. Swap Screens for Sensory Wind-Downs

Replace your pre-bed screen habit with something that engages your senses in a calming way. This could include listening to a sleep hypnosis track, using a weighted blanket, stretching, taking a warm shower, or doing a few minutes of journaling.

4. Keep the Phone Out of the Bedroom

If your phone is your alarm clock, consider switching to a traditional one. Removing your device from arm’s reach reduces the temptation to “just check one thing” that quickly turns into an hour-long scroll.

5. Be Mindful of Content

If you do use screens before bed, steer clear of emotionally charged content. Watching or reading something calm, positive, or even boring (hello, slow documentaries!) is far less likely to disrupt your nervous system than doom-scrolling the news.

A More Peaceful Evening, One Choice at a Time

Improving your sleep doesn’t always mean overhauling your entire life. Often, it starts with one small shift, like putting your phone down 30 minutes earlier or choosing a different way to wind down. Those small decisions compound over time, helping your body return to its natural rhythm and giving your brain the break it truly needs at night.

Sleep isn’t just about rest. It’s about repair, memory, resilience, and mental clarity. And while our screens offer convenience, entertainment, and connection, they’re not neutral tools. How and when we use them matters.

By creating better boundaries with screens, you create space for deeper, more restorative sleep (and all the benefits that come with it!)