The impact of blue light from screens on sleep has been “greatly exaggerated,” according to Michael Gradisar, PhD, with new research showing minimal disruption and a negligible delay in sleep onset.


Summary: New research reveals that blue light from screens has minimal impact on sleep. The study found that screen light intensity is too low to disrupt sleep, with the brightest screens emitting only 80 lux, well below the 500 lux needed to alter sleep timing. Analysis of 11 global studies showed screen use delays sleep onset by just 9.9 minutes. The findings suggest that irregular sleep habits, not screen use, are the primary cause of sleep problems.

Key Takeaways:

  • The study found that screen light, even at its brightest, is not intense enough to disrupt sleep, emitting far below the 500 lux level typically needed to affect sleep timing.
  • Analysis of 11 global studies showed that screen use before bed delays sleep onset by only 9.9 minutes, a difference considered negligible.
  • Engaging with various types of content, including video games and TV shows, has little to no effect on sleep quality, provided regular bedtimes are maintained, according to the findings.

New research challenges the belief that blue light from screens significantly disrupts sleep.

The research, co-authored by Michael Gradisar, PhD, head of sleep science at Sleep Cycle and published in Sleep Medicine Reviews, reviews the relationship between technology use and sleep and reveals that the effects of blue light from screens on sleep are minimal and often overstated.

“If we take a step back and look at everything that can negatively affect your sleep, we see that the effect of screens has been greatly exaggerated,” says Gradisar in a release.

New Findings on Blue Light’s Impact on Sleep

Key findings from the study show that:

  • Light Intensity Matters: The study found that the light emitted from screens is not intense enough to disrupt sleep. In experiments, even the brightest screens did not exceed 80 lux, far below the 500 lux level typically used to change sleep timing (eg, jet lag, shift work, circadian rhythm disorders).
  • 9.9 Minute Delay: Analysis of 11 global studies showed that the maximum delay in sleep onset caused by screen use was only 9.9 minutes, a difference considered negligible.
  • Impact of Content: Contrary to popular belief, engaging with various types of content, including video games and TV shows, had little to no effect on sleep quality as long as individuals maintained regular bedtimes.

“Screen time before bed is often blamed for sleep problems, but our findings show they are not the main contributors. Most sleep problems can be attributed to people having irregular and inconsistent sleep habits,” says Gradisar in a release. “It’s also essential to get an adequate amount of natural light during the day and establish a consistent bedtime routine.”

Exploring New Mechanisms for Technology Use Before Bed

The research team proposed new mechanisms to explain why some individuals might use technology before bed, such as using screens as a tool for emotional regulation and as a time filler. 

The goal of the research was to provide insights and a foundation for future research to explore how technology can be integrated into bedtime routines in a way that supports, rather than hinders, healthy sleep.

“Having Michael Gradisar both as an active researcher and as an internal sleep expert ensures that what we build is backed by science. Michael’s latest research findings challenge the previously held notion that screen time before bed prohibits healthy sleep. This is a major insight that we are excited to share with our one million daily users and can contribute to better sleep health worldwide,” says Erik Jivmark, CEO of Sleep Cycle, in a release.

Photo 62689406 | Bed © Ocusfocus | Dreamstime.com