New research published in the journal JAMA Pediatrics suggests that screen time while in bed negatively impacts sleep more than screen use outside of bed.
The cohort study included 79 young adults ages 11 to 14 years old. The participants wore a body camera for several hours before bed on four nonconsecutive nights to measure their screen time, and infrared cameras placed in their bedrooms measured their screen time after they got into bed. Their sleep duration and sleep quality during this time were measured using a wrist-worn accelerometer. Sleep plays an important role in maintaining mental and physical health, and sleep is considered a key component of cardiovascular health. The goal of this study was to see how screen time before bed and in bed affects sleep quality for young adults.
The results showed that almost all of the participants (99%) used screens in the two hours leading up to bed. More than half of the participants used screens after they got into bed, and about a third used a screen after trying to fall asleep. Interestingly, using a screen in the two hours leading up to bed had no impact on sleep duration or quality. However, using a screen once in bed caused participants to sleep for less time overall. This effect was particularly pronounced if the screen time was more interactive, like playing a game, or if more than one screen was being used at the same time in bed (for example, watching TV on a laptop while playing a game on a phone).
The authors of the study stated that the negative impact on sleep appeared to occur more because of time displacement (staying awake to look at screens during the time allocated for sleep) rather than because of blue light or some other effect. The results of this study suggest that sleep guidelines need to be updated for the modern world, with a particular emphasis on not using screens while in bed.
Sources: JAMA Pediatrics, Science Daily