Do Screens Really Ruin Teen Sleep? Here’s What the Science Says

It’s no secret that screens are a huge part of teenage life. A recent study found that teenagers spend an average of 4.4 hours per day on their smartphones or tablets during the week, and 6.3 hours on weekends¹. Another found that 99% of teens used a screen in the hour before bed².

So, are screens destroying teen sleep?

Well… not quite.

As a sleep psychologist, I often meet families worried about screen time and desperate for guidance. But the truth is more complex than “screens are bad” or “no devices after 8pm.” In fact, many of the messages out there are too simplistic, sometimes misleading, and often unhelpful. It’s time to bust some myths, reduce guilt, and get clear on what the research actually says — and how we can use it to support better sleep.

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The Mixed Messages Around Screens and Sleep

You’ve probably heard this one: no screens two hours before bed. It sounds straightforward. But is it accurate?

The reality is that the scientific evidence is inconsistent. Some studies show associations between screen time and delayed sleep onset or slightly shorter sleep.^{3, 4} Others show no meaningful effects. When effects are found, they’re often tiny — we’re talking 3 to 10 minutes less sleep per hour of screen time⁵.

In fact, when South Korea banned children from accessing the internet between midnight and 6am, researchers found that sleep increased by just 1.5 minutes for boys and 2.7 minutes for girls⁶.

So yes, there’s a link. But the size of the effect is often small, and many studies rely on self-report or mix together different types of screens and behaviours, making it hard to draw clear conclusions⁷.

Instead of strict rules and one-size-fits-all advice, we need nuance — and strategies based on what really drives sleep disruption.

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Why Teen Sleep Is So Tricky

Teen sleep is complex. Their internal clocks naturally shift later, making them biologically prone to going to bed and waking up later. They also build up “sleep pressure” more slowly than younger children, meaning they simply don’t feel sleepy as early.

Add to that increasing autonomy, changing social dynamics, emotional ups and downs, and — yes — engaging technology, and it’s no wonder sleep gets tricky.

But here’s the good news: we can do something about it. Here’s what you need to know.

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The Truth About Blue Light

One common concern is blue light. It’s true that blue light can delay melatonin production — the hormone that helps us feel sleepy — and shift our circadian rhythms.

But here’s the thing: screen light isn’t that bright. The average phone at full brightness gives off 150 lux⁸. Compare that to:

• A cloudy day: 20,000 lux
• A sunny day: 100,000 lux
• Office or classroom lights: 400–600 lux

So yes, screens can impact melatonin slightly — but this doesn’t translate to significant delays in sleep for most people. Studies suggest that it might add about 10 minutes to how long it takes to fall asleep, which is still well within the healthy range.

Bottom line? You can adjust screen settings or use blue-light blocking glasses if you like, but there are usually other factors having a much bigger influence than that screen light.

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It’s the Content That Counts (Sometimes)

Not all screen use is created equal. The impact on sleep depends on what you’re doing and how you’re engaging.

Passive use (like watching a documentary) affects sleep less than interactive use (like gaming or social media)². 

Why? Because when we scroll, game, or check emails in bed, our cognitive and emotional engagement increases. Over time this can create an association between bed and being alert — not sleeping. 

But… as with all things sleep, there is a lot of individual variation. In fact, for teens who regularly play action-packed video games, this activity can be part of a relaxing bedtime routine that doesn’t hinder sleep at all⁹.

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Disruption: The Attention Economy Never Sleeps

Another major issue is disruption. Phones ping, vibrate, and alert us constantly — even during the night.

• Teens who leave the ringer on experience more sleep disturbances and shorter sleep duration¹⁰.
• 70% of teens send at least one text between 10pm and 6am¹¹.
• Nocturnal phone alerts have been linked to significantly higher odds of sleep difficulties one year later¹⁰.

Turning phones off, switching to silent, or charging them outside the bedroom can make a big difference here.

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Or Is It Displacement?

Sometimes, screens don’t interfere with sleep directly — they just displace it.

If a teen watches one more episode, plays one more game, or scrolls for 10 more minutes… that time has to come from somewhere. Often, it’s sleep that is being sacrificed. And a lot of tech companies know that once we’re absorbed in our favourite game or TV series we lose track of time. 

In psychology we call this a state of ‘flow’. That lovely feeling when you’re so engrossed in what you’re doing that you forget everything else – including your bedtime. In fact in 2017 Netflix CEO Reed Hastings said, “we actually compete with sleep… And we’re winning!”. And he could be right. One study found that teens in a flow state went to bed 90 minutes later than their peers¹¹.

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Emotional Regulation and Tech Use – When can screens be helpful?

It’s easy to assume screens are always stimulating. But they can also be soothing.

• 62% of teens report using tech to distract from negative thoughts¹¹.
• Some use apps for guided meditation, mindfulness, or therapy.
• Others seek connection or support via social media.

In these cases, screens can be helpful — especially during stressful periods. But they can also reinforce habits that keep us alert in bed. If you feel wide awake the moment you get into bed and reach for your phone to unwind, that’s a sign you might be building a pattern that keeps you stuck.

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The Role of Self-Control, FoMO, and Bedtime Procrastination

Teens are still developing their self-regulation skills. Their prefrontal cortex — the brain’s self-control centre — isn’t fully developed, which makes resisting temptation harder¹¹.

Throw in features like autoplay, infinite scroll, and the pressure to always be available, and you’ve got a recipe for bedtime procrastination.

FoMO (Fear of Missing Out) is a real issue, especially when logging off feels like social exclusion. This is why empathy, not punishment, is crucial. Many teens want help setting limits — even if they don’t always admit it.

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So, What Can We Do?

This isn’t about banning screens or enforcing rigid rules. It’s about helping teens build self-awareness, healthy boundaries, and sustainable habits.

Here are some evidence-based strategies:

1. Collaborate on rules

Setting consistent tech and sleep rules leads to earlier bedtimes and longer sleep (11). But rules are most effective when developed with your teen — not imposed on them.

2. Target your efforts

Not all teens are the same. Some are hooked on gaming, others scroll to soothe anxiety. Be curious about why your teen uses screens — and tailor your approach accordingly.

3. Minimise the temptation

• Use “do not disturb” or silent modes overnight
• Encourage charging phones outside the bedroom
• Encourage social media curfews agreed with friends

4. Model healthy habits

If you’re scrolling at midnight, your teen is watching. Family-wide tech curfews or screen-free zones can help everyone sleep better.

5. Support emotional regulation

Rather than removing all screen-based coping tools, help your teen find tech and non-tech strategies to manage emotions. Mindfulness apps, journaling, talking things through — all can support better sleep.

6. Be realistic and flexible

Don’t try to change everything at once. Pick one or two changes to focus on. See what works. Adjust. It’s a marathon, not a sprint.

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Final Thoughts

Sleep and screen use are deeply personal. What disrupts one teen may help another. And while screens can interfere with sleep, the impact is often small — unless there are other factors involved, like emotional distress, lack of boundaries, or underlying sleep issues.

The key is not to panic. Get curious. Be empathetic. Support your teen in understanding their own sleep needs — and using tech wisely.

And remember: absence of evidence is not evidence of absence. There’s still a lot we don’t know. But one thing is clear: empowering teens to manage their own habits is far more effective than fighting nightly battles over phone chargers.

Which one of these tips are you going to try this week?