Impact of screens

Despite common belief, up to 50% of parents believe that watching TV helps their child "wind down" after a long day, research suggests that screens are more harmful than calming. [4] In the last 5-10 years there has been a drastic change from watching information on TV to using more mobile light-emitting devices (such as phones, tablets, and laptops); prolonging the time and exposure of blue lightwaves from screens before sleep. Along with your own personal experiences, numerous researchers have associated the use of light-emitting screens before bed with poorer sleep quality, later bedtime, and shorter sleep duration. [4] In Hale et al's literature review about screen media habits and sleep they discovered that in 90% of the studies they included there was a direct association between screen media use and delayed sleep across all age groups.

But what are the mechanisms that cause this consequence of this screen use?

They came to conclude that the three main mechanisms were delaying bedtime, mental stimulation from the content, and physical alertness due to the exposure of light from the screens. The screen usage in turn increased alertness due to producing hormones in response to blue light. The CDC discovered that blue light is particularly disruptive to the circadian rhythm by delaying the onset of sleep. [5] Therefore postponing when you go to sleep, as it reduces sleepiness, resulting in less time spent asleep and negatively affecting your sleep duration.

Another study was based on a large-scale cross-sectional study in Norway replicated these findings while strengthening that adolescents (aged 16-19 years old) tend to have a dose-response relationship between sleep and electronic use. [6] This means that the higher the amount of something (in this case screen use) negatively affects the response and outcome of sleep efficiency. Both of these studies provide evidence that demonstrates the harmful effects of screen use on sleep. The research emphasizes the role that blue light plays in interfering with the body's natural homeostatic circadian rhythm. This not only reduces the length but also the quality of sleep which can have long-term consequences on one's health.

Advice from current research recommends building healthy media use techniques and habits as well as limiting exposure to electronic devices at least 1-2 hours before sleep to avoid disrupting the natural circadian rhythm and increasing arousal.