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.
This guide reviews the evidence, explains what the large 2025 Norwegian student study actually tells us, and suggests changes that are realistic for screen-heavy lives.
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]
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
Screen 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
Evening 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
Work 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
Sound, 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
The 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
Try 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
Reduce 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
Use Do Not Disturb or another focus setting. Allow exceptions for people or alerts genuinely needed for emergencies.
Move the Phone Out of Reach
Charge 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
Audio 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.
| Step | What to do | What to track |
|---|---|---|
| 1 | Choose one rule: no screens in bed, or a planned stopping point. | Whether you followed the rule each night. |
| 2 | Silence nonessential notifications overnight. | Nighttime checking and remembered awakenings. |
| 3 | Record when you put the final screen away. | Intended bedtime and actual lights-out time. |
| 4 | Estimate how long it took to fall asleep. | Sleep onset, awakenings and wake time. |
| 5 | Rate morning alertness from 1 to 5. | Whether any improvement is consistent. |
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 single cutoff that works for everyone. Keeping screens out of bed and trying a 30–60 minute lower-stimulation period is a sensible place to begin. Adjust it according to your schedule and response.
Is reading on a tablet before bed as bad as scrolling social media?
Both can push sleep later if they keep you on a device after bedtime. Interactive or emotionally engaging content may feel more alerting, but the 2025 study could not show that every activity affects sleep in the same way.
Do blue-light glasses reliably improve sleep?
Blue-light-blocking glasses reduce some short-wavelength light, but evidence that they reliably improve sleep is mixed. They do not prevent bedtime delay or mental stimulation.
Does television affect sleep in the same way as phone use?
Both can extend screen use into the sleep period, but they differ in distance, brightness and interactivity. The available study found no clear difference across broad activity types, but television and phone use still differ in distance, brightness and interactivity.
What is a practical first change to try?
Keep the phone out of the bed, silence nonessential notifications and set a planned stopping point. Track whether this changes bedtime, sleep duration or morning alertness.
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 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.
