The presence and use of these devices is incredibly widespread.
A 2006 survey showed that nearly all adolescents have at least one electronic device in their bedroom.
Given this, and the increasing exposure to screens - particularly in the hours before bedtime - it is perhaps not surprising that screen time is now associated with insufficient and poor-quality sleep.
A 2014 review found consistent evidence that sleep was hampered by screen time, primarily in relation to shortened duration and a delay in the onset of sleep. The latter finding was reported in 90 per cent of the studies reviewed.
But the relationship between screen time and sleep is more complex than that. Screen time could be negatively influencing sleep in many ways.
The timing of screen time is one important factor. The use of these devices can lead to delays in the time that children and adolescents go to bed and, consequently, have a shorter sleep overall.
These negative impacts can be due to screen time in the evening cutting into the time that children would normally be preparing for bed, delaying sleep onset and reducing the overall duration of sleep. There is simply less time available for it.
It has also been suggested that longer screen time may be affecting sleep by reducing the time spent doing other activities - such as exercise - that may be beneficial for sleep regulation.
Bright lights and alertness
Screen time in the hours directly prior to sleep is problematic in a number of ways other than just displacing the bedtimes of children and adolescents. The content of the screen time, as well as the light that these devices emit, may also be responsible for poorer sleep.
The content young people are engaging with on screen can be detrimental to sleep.
For example, exciting video games, dramatic or scary television shows, or even stimulating phone conversations can engage the brain and lead to the release of hormones such as adrenaline. In turn, this can make it more difficult to fall asleep or maintain sleep.
Less obvious, but just as important, is the impact that light has on sleep.
Many of the devices that are now routinely used by young people emit bright light.
Exposure to these light emissions in the evening hours before sleep can increase alertness.
Bright light at night can also disrupt the body's naturally occurring circadian (or daily) rhythms by suppressing the release of the hormone melatonin, which is important for maintaining and regulating the sleep-wake cycle.
Limiting screen time to improve sleep
The number of devices and amount of screen time children and adolescents are exposed to is continually increasing.
Given these early associations with reduced sleep quality, and the importance of sleep in healthy growth and development, this is an issue that is not likely to go away any time soon.
Sleep should be made a priority, and we can combat this growing problem in a number of ways.
It is becoming increasingly clear that limiting screen time in the period leading up to bedtime is beneficial for sleep.
In relation to this, removing electronic devices from the bedroom provides a good sleep environment and promotes good sleep practices.
Although it is yet to be established how much is too much when it comes to screen time, public guidelines recommend that children under the age of 13 are limited to two hours a day, and children below 5 to less than one hour.
There are many advantages to the advancements in technology that go alongside the exposure to screen time, such as broader opportunities for learning and communicating.
However, the worrying trend of increased screen time at the cost of essential behaviours such as sleep should not be ignored.
With a more balanced approach to screen time and the use of electronic devices, the clear benefits can be obtained while still maintaining and prioritising sleep, health and development.
Sarah Loughran is a research fellow at University of Wollongong.
• theconversation.com/au
