Bedtime screen use is linked with later and shorter sleep, but the explanation is more complicated than “blue light is bad.” Devices may replace sleep time, expose the eyes to evening light, keep the mind engaged and encourage overnight checking.
Rather than blaming every poor night on blue light, this guide explains what researchers have found and helps you test changes that fit everyday life.
Key Takeaways
- Bedtime screens may affect sleep through time displacement, evening light, mental arousal and nighttime checking.
- The 2025 study found strong associations, but because it was cross-sectional, it cannot tell us which came first.
- Night mode and blue-light-blocking glasses may reduce some light exposure, but they still leave the bigger issues of bedtime delay and stimulating content untouched.
- A useful first experiment is to keep screens out of bed, silence nonessential alerts and set a planned stopping point.
How Screen Use May Affect Sleep
Bedtime screen use is not one single exposure. A dim e-reader used briefly is different from an hour of interactive gaming, work messages or short-form video after getting into bed. Device brightness, viewing distance, room lighting, content, timing and the total minutes spent all matter.
Laboratory research has shown that prolonged evening use of a light-emitting e-reader can suppress melatonin, delay circadian timing, increase the time needed to fall asleep and reduce next-morning alertness compared with reading a printed book.[2] That finding shows that evening light can matter under controlled conditions. A quick glance at a phone, though, is not the same exposure as prolonged e-reader use in a laboratory.
What the 2025 Study Found
A 2025 cross-sectional study analysed data from more than 45,000 Norwegian full-time university students aged 18–28. Among participants using screens in bed, each additional hour of screen use after going to bed was associated with 59% higher odds of reporting insomnia symptoms and approximately 24 minutes less self-reported sleep.[1]
How to interpret the percentages
Higher odds is not the same as 59% more people developing insomnia. The result describes a statistical association within this student sample; it is not a forecast of what happens if an individual uses their phone for another hour.
Likewise, reducing your own screen use by one hour does not guarantee 24 extra minutes of sleep. What changes for you depends on bedtime, content, stress, health and other factors.
The researchers did not find a clear difference between participants who reported only social media and those who reported other or mixed screen activities.[1] That still leaves room for different activities to affect people in different ways.
What the Study Cannot Prove
The study was observational and cross-sectional, and screen use and sleep were self-reported. The study cannot tell whether screen use led to poorer sleep, whether people who were already struggling to sleep reached for their devices more often, or whether another factor influenced both.[1]
Its broad activity categories also combined experiences that may differ in brightness, emotional content, interactivity and difficulty stopping. So the lack of a clear difference between categories should not be read as evidence that television, reading, gaming and social media affect everyone in exactly the same way.
Four Possible Ways Screen Use May Affect Sleep
Time Displacement
How it may affect sleepScreen use can directly replace sleep. Ten more minutes becomes thirty, and bedtime moves later even when the person feels able to fall asleep once the device is put down. The 2025 researchers considered displacement a particularly plausible explanation for their results.[1]
Evening Light
How it may affect sleepEvening light containing short wavelengths can suppress melatonin and influence circadian timing under some conditions. The size of the effect depends on brightness, timing, duration, distance, screen size, wavelength and surrounding light.[2]
Cognitive or Emotional Arousal
How it may affect sleepWork email, upsetting news, conflict, competitive games or difficult-to-stop feeds may keep attention and emotions activated. In a study of adolescents, nighttime social-media use was associated with greater pre-sleep cognitive arousal, later bedtimes and longer sleep-onset latency, although the observational design did not establish causality.[10]
Notifications and Overnight Checking
How it may affect sleepSound, vibration or screen illumination may wake you or prompt checking during the night. A longitudinal adolescent study linked mobile-phone-related nighttime awakenings with later sleep problems and related symptoms; the age group and observational design limit how broadly the result should be applied.[11]
Do Night Mode and Blue-Light Glasses Help?
Night Mode
Night mode reduces short-wavelength light and may make a display feel more comfortable in a dark room. However, a randomized trial involving 167 emerging adults found no overall sleep differences between Night Shift enabled, Night Shift disabled and no-phone conditions. Among participants already obtaining adequate sleep, avoiding the phone performed better on some outcomes than using it with Night Shift.[3]
Night mode can make the display easier on the eyes, but it does not replace actually putting the device away.
Blue-Light-Blocking Glasses
A systematic review and meta-analysis of interventions that reduced short-wavelength light found mixed effects across studies and populations.[4] A later Cochrane review concluded that blue-light-filtering spectacle lenses may not provide meaningful short-term benefits for several commonly marketed outcomes and that the evidence for sleep effects remained uncertain.[5]
Blue-light glasses may reduce part of the light exposure, while bedtime delay, difficult-to-stop content, work stress and overnight notifications can still remain.
Realistic Strategies for Screen-Heavy Lives
Keep Screens Out of the Bed
Practical stepThe boundary “not after getting into bed” is often easier to apply than banning all evening technology. Use the device elsewhere, then enter the bed when you are ready to sleep.
Set a Planned Stopping Point
Practical stepTry a screen-free or lower-stimulation period before bed. Thirty to sixty minutes is a reasonable place to start, and you can adjust from there based on your schedule and response.
Reduce Hard-to-Stop Content First
Practical stepReduce work messages, stressful news, arguments, competitive games and feeds that encourage endless scrolling. Even calm content can delay bedtime if it continues longer than planned.
Silence Nonessential Notifications
Practical stepUse Do Not Disturb or another focus setting. Allow exceptions for people or alerts genuinely needed for emergencies.
Move the Phone Out of Reach
Practical stepCharge it across the room or outside the bedroom when practical. A separate alarm clock can remove the most common reason for keeping the phone beside the pillow.
Use Audio Carefully
Practical stepAudio without a bright screen may be easier for some people, but autoplay, stimulating content or uncomfortable earbuds can still interfere. Use a sleep timer and a safe volume.
A One-Week Screen-and-Sleep Experiment
Instead of assuming screens are the cause, test one clear change and observe what happens. Keep the rest of your routine as stable as reasonably possible.
1. Choose one clear rule
Keep your phone out of bed or set an end time for optional screens. Changing one rule makes patterns easier to interpret.
Record: whether you followed the rule that evening.
2. Keep necessary alerts
Silence nonessential notifications but allow important emergency or caregiving calls.
Record: overnight checking or interruptions you remember.
3. Note actual sleep times
Write when you put the last screen away, attempted to sleep and finally woke.
Record: approximate sleep timing, not only planned bedtime.
4. Check the morning
Rate morning alertness from 1 (very sleepy) to 5 (well rested). Avoid treating one night as proof.
Look for: a pattern across the whole week.
Copyable seven-night sleep log
Copy these lines into your notes. Track what actually happened rather than trying to complete a perfect score.
- Night 1Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 2Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 3Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 4Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 5Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 6Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
- Night 7Last screen: ____ | Sleep attempted: ____ | Wake: ____ | Alertness (1–5): ____
Review: Did your stopping time change? Did you attempt sleep earlier? Was morning alertness consistently different? The log cannot diagnose a sleep condition.
A randomized pilot trial found improvements after restricting bedtime mobile-phone use, although the study was small and the same rule may not work equally well for everyone.[6]
Clues That Screen Habits May Be Worth Testing
- You regularly stay awake longer than intended because you continue using a device.
- You get into bed on time but do not attempt sleep until much later.
- You feel mentally activated after work, conflict, gaming or difficult-to-stop content.
- You wake and check notifications during the night.
- Your sleep improves on nights when the phone is not in bed.
These clues are not a diagnosis of the problem, but they are good reasons to try a structured one- or two-week test.
Objective smartphone-tracking research has also found that greater screen time, particularly around the sleep period, can be associated with poorer self-reported sleep, while still leaving questions about causality.[7]
When Screen Changes Are Not Enough
Reducing screen use may help, but poor sleep can have many other causes. Speak with a qualified healthcare professional when sleep problems are persistent, affect daily functioning or create safety risks.
- Frequent loud snoring, gasping or witnessed pauses in breathing
- Severe daytime sleepiness or falling asleep while driving, working or studying
- Regular difficulty falling asleep, staying asleep or waking too early
- Sleep problems lasting for months despite reasonable habit changes
- Anxiety, depression, pain, reflux or medication that may be affecting sleep
Breathing that starts and stops, frequent loud snoring, gasping and significant daytime sleepiness are recognised sleep-apnea symptoms and should be assessed.[8]
Frequently Asked Questions
How long before bed should I stop using screens?
There is no proven cutoff that suits everyone. Try keeping screens out of bed, or stop stimulating screen activities about 30 to 60 minutes before you intend to sleep. The important test is whether you consistently make enough time for sleep.
Is a tablet book different from scrolling social media?
Both can delay bedtime if you keep using them past your planned stopping point. A calm book may feel less stimulating than interactive social media, but brightness, content, timing and how long you use the device also matter. The Norwegian survey cannot establish which activity causes more sleep problems.
Do blue-light glasses reliably improve sleep?
Not reliably. The Cochrane review found that effects on sleep were uncertain, with inconsistent results from small trials. Glasses cannot address delayed bedtime, stress, stimulating content or notifications.
Does television affect sleep in the same way as a phone?
Not necessarily. Televisions and phones differ in distance, brightness, interactivity and how easily they can be used in bed. Any of them can shorten sleep if viewing delays bedtime. Evidence does not support assuming they affect every person identically.
What is a practical first change to try?
Keep the phone out of bed or choose a firm stopping point, then silence unnecessary overnight alerts. Record when the last screen was put away, the time you attempted sleep and morning alertness for a week.
Can using my phone at night cause insomnia?
Screen use in bed is associated with insomnia symptoms in observational research, but those studies do not prove that screens cause insomnia. Persistent difficulty sleeping can have several causes and may require professional assessment.
What if I need my phone for emergencies or on-call work?
Keep necessary calls or emergency contacts enabled and silence nonessential notifications. If you must remain on call, try to avoid unrelated scrolling, reduce brightness and decide in advance when to stop optional screen use.
Is audio or a podcast before bed a better option?
Some people find audio without a bright display less disruptive, particularly with a sleep timer and calm content. Audio is not automatically helpful if it delays bedtime, becomes stimulating or requires frequent phone interaction.
When should I seek help rather than changing screen habits?
Speak with a healthcare professional if sleep difficulties persist, if daytime sleepiness affects work or driving, or if you notice loud snoring, gasping or breathing pauses. Cognitive behavioural therapy for insomnia is a recommended treatment for chronic insomnia; screen restrictions alone are not a treatment for it.
A Practical Next Step
For the next seven nights, choose just one change: either keep your phone out of bed or set a planned screen stopping point. Silence nonessential overnight notifications and note whether your bedtime, sleep duration or morning alertness changes.
If the change helps, keep it. If it does not, avoid assuming screens are the whole problem, persistent sleep difficulty may need a broader sleep review or professional assessment.
Final Thoughts
Screen use can affect sleep through more than blue light. Time spent on a device can replace sleep, stimulating content can delay disengagement, evening light can influence circadian biology under some conditions, and notifications can encourage overnight checking.
You probably do not need an expensive filter or an all-or-nothing digital detox. Start with a few simple changes: keep screens out of bed, choose a stopping point, silence nonessential alerts and see whether your sleep improves. If late-night screen use has already shifted your bedtime and wake time far from where you need them, use How to Fix Your Sleep Schedule Gradually and Safely for a step-by-step reset. If those changes make little difference and sleep problems remain persistent or severe, it is worth looking beyond screens and seeking an appropriate assessment.
If screens are only one part of your sleep problem, see our complete guide to how to sleep better for a broader plan covering sleep duration, quality, schedules, daytime habits and bedtime routines.
References
- Hjetland GJ, Skogen JC, Hysing M, Gradisar M, Sivertsen B. How and When Screens Are Used: Comparing Different Screen Activities and Sleep in Norwegian University Students. Frontiers in Psychiatry. 2025.
- Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening Use of Light-Emitting eReaders Negatively Affects Sleep, Circadian Timing, and Next-Morning Alertness. Proceedings of the National Academy of Sciences. 2015.
- Duraccio KM, Zaugg KK, Blackburn RC, Jensen CD. Does iPhone Night Shift Mitigate Negative Effects of Smartphone Use on Sleep Outcomes in Emerging Adults? Sleep Health. 2021.
- Shechter A, Quispe KA, Mizhquiri Barbecho JS, Slater C, Falzon L. Interventions to Reduce Short-Wavelength (“Blue”) Light Exposure at Night and Their Effects on Sleep: A Systematic Review and Meta-Analysis. Sleep Advances. 2020.
- Singh S, Downie LE, Anderson AJ, et al. Blue-Light Filtering Spectacle Lenses for Visual Performance, Sleep, and Macular Health in Adults. Cochrane Database of Systematic Reviews. 2023.
- He JW, Tu ZH, Xiao L, Su T, Tang YX. Effect of Restricting Bedtime Mobile Phone Use on Sleep, Arousal, Mood, and Working Memory: A Randomized Pilot Trial. PLOS ONE. 2020.
- Christensen MA, Bettencourt L, Kaye L, et al. Direct Measurements of Smartphone Screen-Time: Relationships with Demographics and Sleep. PLOS ONE. 2016.
- National Heart, Lung, and Blood Institute. Sleep Apnea: Symptoms.
- Edinger JD, Arnedt JT, Bertisch SM, et al. Behavioral and Psychological Treatments for Chronic Insomnia Disorder in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline. Journal of Clinical Sleep Medicine. 2021.
- Scott H, Biello SM, Woods HC. Fear of Missing Out and Sleep: Cognitive Behavioural Factors in Adolescents’ Nighttime Social Media Use. Journal of Adolescence. 2019.
- Foerster M, Henneke A, Chetty-Mhlanga S, Röösli M. Impact of Adolescents’ Screen Time and Nocturnal Mobile Phone-Related Awakenings on Sleep and General Health Symptoms: A Prospective Cohort Study. International Journal of Environmental Research and Public Health. 2019.
