Why we need to teach kids to balance screen-time and green-time – Part 2

// Mind-wandering mode

Time unplugged and in nature allows our students’ brains to enter what neuroscientists call ‘mind wandering mode’ which is also considered the ‘default mode’ of thinking. When our students are outdoors, they’re away from their screens (hopefully) and therefore they’re not processing the multitude of sensory input that screens offer (sounds, animations, graphics, text). This allows their prefrontal cortex (the part of the brain that’s responsible for their higher-order thinking) to switch off. As a result, their mind can wander. During this mode of thinking, they can come up with creative solutions to problems, develop new ideas and be creative. (This is also the exact same reason why we often have our best ideas in the shower, after a run, or after a holiday.)

// Circadian rhythms to regulate sleep

Students’ brains release hormones to regulate body functions such as appetite, mode, energy and sleep. These daily cycles are called ‘circadian rhythms’. However, these cycles can be adversely impacted if kids don’t get enough light, or if they get too much light, or if they’re exposed to the wrong types of light (such as blue light, as later explained in this section). Our kids’ screen habits are definitely having a major impact on their circadian rhythms.

Time outdoors in sunlight can be a wonderful (and simple) anecdote to kids’ increasing screen use.This exposure is important to regulate students’ circadian rhythms which they require for healthy sleep. Research tells us that exposure to sunlight in the mornings can help to regulate circadian rhythms. When this strategy is coupled with enforcing a ‘digital bedtime’ for devices, at least 60 minutes before sleep time, this can optimise kids’ sleep habits.


Given that many students, not just adolescents are using screens more frequently and often before sleep time then they’re being exposed to too much blue light. Blue light that’s emitted from tablets and computers can impact their sleep because it suppresses the body’s production of melatonin which they need to fall asleep quickly and easily. In turn, this can delay the onset of sleep

// Increase physical activity levels

When students are outside they tend to engage in physical activity. It’s well established that physical activity has a multitude of benefits for students’ physical, mental and emotional health. In years gone by students engaged in significantly more incidental physical activity, but given the prevalence of screens, coupled with over-scheduled childhoods, there’s now less time available for incidental physical activity.

// Attention restoration theory

Time in nature has also been shown to calm the brain and help to reorient students’ attentions. This is referred to as the ‘attention restoration theory’.  Time on screens often causes hyper-arousal and overloaded nervous systems (this is one of the reasons why kids have techno-tantrums when they’re asked to switch off devices). However, unplugged time spent outdoors is typically slower-paced than the on-screen action kids are encountering. As a result it gives their nervous system and their brains a break from the constant sensory smorgasbord that the online world offers. This has a restorative effect and allows students to better manage their attention.

// Promotes visual health

There are increasing rates of children and adolescents being diagnosed with myopia, nearsightedness. Although unproven by research at this stage, ophthalmologists and researchers agree that the premature introduction of screens and excessive time with screens, coupled with genetic factors, are to blame.


There are public health campaigns in some Asian countries such as ‘Keep myopia away, go outdoors and play’ which warn of the perils of too much time on screens and one of the (many) health consequences associated with excessive screen-time.


Some preliminary research suggests that time outdoors in nature can help to minimise the onset of myopia for two reasons: (i) exposure to natural light is critical for healthy visual development and (ii) viewing distances are greater outside, as opposed to looking predominantly at things close distance.


Dr Kristy is a leading digital wellness expert (and Mum!) who’s on a mission to take the guesswork and guilt out of raising and teaching kids in the digital world. Kristy is an author, speaker and researcher and speaks to parents, educators and health professionals throughout Australia and internationally. She delivers teacher professional learning workshops and parent seminars in schools throughout Australia about how children’s digitalised childhoods are impacting their health and wellbeing. She delivers a practical workshop specifically designed for educators called Healthy Digital Habits where she provides simple, practical strategies for primary and secondary teachers to help them develop healthy and helpful technology habits with students (without digitally amputating our kids). You can find more information about the topics Kristy presents at www.drkristygoodwin.com.

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