Technology’s Impact on Sleep
Evening screen use, from phones to tablets, affects sleep in two important ways: by exposing you to blue‑wavelength light, which interferes with melatonin production, and by mentally stimulating your brain right before it should be shutting down.
How Screens Affect Sleep
When you're exposed to blue light, around 480 nm, from screens in the hour before bed, your brain’s internal clock gets shifted, and melatonin is suppressed, making it harder to fall asleep naturally (Silvani et al., 2022; Chang et al., 2015). A large adult cohort study (Cancer Prevention Study‑3) found that using screens before bed raised the prevalence of poor sleep quality by about 33% and coincided with an average loss of roughly 7 to 8 minutes of nightly sleep, especially among people who tend to go to bed late (Zhong et al., 2025).
Among children and teens, the effects are even more consistent: a wide review of more than 60 studies reported that 90% showed screen use at bedtime was linked to delayed sleep onset or reduced total sleep time (Hale et al., 2018). Meanwhile, a large student survey found every additional hour of screen use in bed corresponded with a 59% higher odds of insomnia symptoms and 24 fewer minutes of sleep (Hjetland et al., 2025).
Can Night‑Mode or Blue‑Light Filters Help?
Using screen filters or “night‑mode” settings may reduce melatonin suppression modestly, but evidence suggests their real-world impact on sleep quality is limited. One study found blue‑light filters did not reliably improve sleep outcomes over time (Rabiei et al., 2024). Experts now emphasize that what you do on screens—like watching exciting shows or scrolling social media: often matters more for sleep disruption than light exposure alone (Hartstein et al., 2024; Gradisar et al., 2024).
Practical Advice: When to Stop, and When to Start
It’s best to power down screens at least 60 minutes before bedtime, allowing melatonin to rise and your circadian rhythm to align with night. Put devices on silent and charge them outside the bedroom to avoid interruptions. In the morning, give yourself 15 to 20 minutes before using a phone or tablet: stretch, hydrate, or journal first to let your mind warm up gently.
Kid‑Friendly Science to Share
Think of your body’s sleep signal, melatonin, as a “nighttime switch.” Exposure to blue light fools your brain into thinking it’s still daytime, delaying that switch. At the same time, engaging content keeps your brain active instead of winding down. Filters help a bit, but what really works is giving your brain a little grace before bedtime.
Summary Tips for Better Sleep and Tech Use
Avoid screens for at least an hour before bed. If you must use devices in the evening, stick to passive content like familiar music or a calming show. Charge electronics outside your bedroom. Delay check-ins in the morning until your mind has fully woken up. Blue-light filters may offer minor help—but they’re not a substitute for healthy screen boundaries.
References:
- Chang, A. M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences of the United States of America, 112(4), 1232–1237. https://doi.org/10.1073/pnas.1418490112
- Hartstein, L. E., Mathew, G. M., Reichenberger, D. A., Rodriguez, I., Allen, N., Chang, A. M., Chaput, J. P., Christakis, D. A., Garrison, M., Gooley, J. J., Koos, J. A., Van Den Bulck, J., Woods, H., Zeitzer, J. M., Dzierzewski, J. M., & Hale, L. (2024). The impact of screen use on sleep health across the lifespan: A National Sleep Foundation consensus statement. Sleep health, 10(4), 373–384. https://doi.org/10.1016/j.sleh.2024.05.001
- Hale, L., Kirschen, G. W., LeBourgeois, M. K., Gradisar, M., Garrison, M. M., Montgomery-Downs, H., Kirschen, H., McHale, S. M., Chang, A. M., & Buxton, O. M. (2018). Youth Screen Media Habits and Sleep: Sleep-Friendly Screen Behavior Recommendations for Clinicians, Educators, and Parents. Child and adolescent psychiatric clinics of North America, 27(2), 229–245. https://doi.org/10.1016/j.chc.2017.11.014
- Hjetland, G. J., Skogen, J. C., Hysing, M., Gradisar, M., & Sivertsen, B. (2025). How and when screens are used: comparing different screen activities and sleep in Norwegian university students. Frontiers in psychiatry, 16, 1548273. https://doi.org/10.3389/fpsyt.2025.1548273
- Rabiei, M., Masoumi, S. J., Haghani, M., Nematolahi, S., Rabiei, R., & Mortazavi, S. M. J. (2024). Do blue light filter applications improve sleep outcomes? A study of smartphone users' sleep quality in an observational setting. Electromagnetic biology and medicine, 43(1-2), 107–116. https://doi.org/10.1080/15368378.2024.2327432
- Silvani, M. I., Werder, R., & Perret, C. (2022). The influence of blue light on sleep, performance and wellbeing in young adults: A systematic review. Frontiers in physiology, 13, 943108. https://doi.org/10.3389/fphys.2022.943108
- Zhong, C., Masters, M., Donzella, S. M., Diver, W. R., & Patel, A. V. (2025). Electronic Screen Use and Sleep Duration and Timing in Adults. JAMA network open, 8(3), e252493. https://doi.org/10.1001/jamanetworkopen.2025.2493