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Why does this matter?

Screen-based digital technologies present both benefits and risks to children and teenagers.

Understanding these can help us support young people to maximise the opportunities that digital technologies afford, with lower risk.

This section will review the risks associated with screen use, summarise current research and offer solutions.

Key Takeaways

Some screen use can benefit not only learning, but also health and wellbeing, particularly for adolescents. Accessing health promoting information, connecting with friends and exercise-based gaming (such as Wii) are just a few examples.
For ideas on great use of tech to support learning, see ‘What’s going well’.
Frequent and extended screen use is linked to negative impacts on learning, health and wellbeing. 
Risks linked to screen use are a significant concern for many parents and professionals, and research has found it is the top child health concern for parents. Adolescents are also recognising an issue, with 90% of teens saying ‘spending too much time online is a problem for teenagers’ (and 60% saying it’s a major problem).
Learn more about:
Physical and mental health
Neurological impacts
Social / emotional impacts

Physical and mental health


Some use of digital technologies can support learning, health/wellbeing and having fun, especially for older children and adolescents.


Research into the impacts of screen use on child and adolescent health/wellbeing is not conclusive, and more long-term studies are needed. However, the current evidence is broad and growing.


Frequent use of digital devices has been linked to harm across numerous areas of health, including:

Eye health

Digital eye strain (eye discomfort and/or visual symptoms related to screen use) is a common issue, and up to 90% of users with more than three hours of screen time experience symptoms, according to the US National Institute of Occupational Health and Safety. These symptoms seem mostly related to time spent on screens, regardless of the activities the person is doing (screen media content). That means ‘the impacts don’t really change based on whether a child is playing games, using social media or doing schoolwork’. While symptoms can occur within shorter timeframes, a number of studies have found that four to five hours of screen use per day could be a critical duration to cause digital eye strain. Teaching habitual blinking, ergonomics, having regular screen breaks and time limits may help.

Dry eye disease, where an insufficient tear film causes permanent damage to the surface of the eye, has been directly associated with screen use, also regardless of screen media content. Hours of daily screen use in children have been found to predict number of symptoms. Limiting screen use and teaching habitual blinking could reduce these risks.


A significant increase in childhood myopia (short-sightedness) is thought to be due to a displacement of outdoor activity associated with increased screen use. Limiting screen use and increasing outdoor time are commonly advised by children's eye doctors to reduce myopia risks.


Headphone use is associated with hearing loss in children, due to not only volume but length of exposure. The World Health Organisation has highlighted headphone/earbud use with devices as a significant risk to hearing for young people. To reduce these risks, experts advise the less time spent using headphone and earbuds, the lower the risk of hearing loss. Further advice is to listen at the lowest volume children can hear clearly with, and to use noise-cancelling and volume limited headphones.



The majority of studies investigating screen use and sleep have found that frequent screen use and bedtime screen use are linked to sleep disturbance in children and teens. A balance of digital and non-digital activities during the day, no screen use in the hour before sleep, and removing screens from bedrooms may help children to sleep well.


Physical Health

Headaches, neck and back pain and Repetitive Strain Injury (RSI) have been linked to frequent screen use, regardless of screen media content. Large-scale studies have found that the more hours of daily screen use adolescents report, the more they report symptoms of back pain. Research is limited in physical health, but Worksafe NZ recognises these risks and provides ergonomic guidance for the safe use of digital devices by adults in the workplace. Ergonomic advise and appropriate furniture in schools may reduce risk, along with a balance of time spent on and off screens.



The World Health Organization has noted that high screen use can replace more active behaviours, and numerous studies have found a link between frequent screen use and obesity. More evidence is needed, but encouraging a balance of active behaviours and moderate screen use could support children and young people with healthy weight.

Content matters, but so does time spent using screens



Children’s brains change in response to experiences.


For school-aged children, some screen use can support development, particularly when it is educational, appropriate to the child’s age and especially when an adult is sharing the experience.


Frequent screen time is linked to poorer developmental outcomes (especially for younger children). However, screen media content and context of use also influence children's development, and may have more impact than time spent using screens.

Screen time and brain structure

A study of 4,500 9 and 10-year-olds found that many of those who spent more than seven hours a day on screens had premature thinning of their cerebral cortex, the area of the brain involved in higher order thinking. Whether the screen time caused the thinning or children with prematurely thinned cortexes are likely to have more screen time is unclear. The study is ongoing and future results will help to clarify cause and effect.

MRI studies on preschoolers with screen time in excess of guidelines found lower integrity of white matter in the brain, in areas of language and emergent literacy, along with reduced performance on behavioural tests. 



Studies have found an increased risk of behavioural problems including inattention, and lower cognitive skills in young children with higher screen use. This includes research by Tamana et al (2019) which found that children exposed to two hours of screen use per day were seven times more likely to meet the criteria for ADHD than children with half an hour of screen use per day, at age 3 and 5 years. 'The two big takeaways from this study are that children exposed to more screen time, at either age 3 or 5 years, showed significantly greater behavioural and attention problems at age 5, and that this association was greater than any other risk factor we assessed, including sleep, parenting stress, and socioeconomic factors,'noted author Sukhpreet Tamana, a postdoctoral fellow in the Department of Pediatrics at the University of Alberta. Research has shown similar effects on attention at 4.5 years of age in young children exceeding one hour of screen use per day.


These studies show negative associations with screen use and attention for younger children, however, recent studies have found similar associations for teenagers. While duration of screen use is commonly studied, more research is needed to understand the role that screen media content and context play in these findings.


Gaming and social media

Gaming is thought to have both positive and negative consequences on children’s development. MRI studies have shown a correlation between gaming and anatomical impacts on brain reward centres and structure. Some changes have positive inferences, such as increased grey matter in brain areas involved with visual navigation and strategic planning, during games with strategy content. Other studies show reduced cortical grey matter and myelination in certain areas. Reward-based gaming has been linked to structural brain changes in the reward circuitry that resemble the effects of substance addiction. Long-term outcomes on behaviour are unknown. Researchers hypothesise that 'excessive usage could be changing children’s brain reward systems in the long term, making them more susceptible to other addictions later in life.' Problematic social media use has also been linked to the same structural changes to brain appearance as substance addictions. This research is in the early stages and there are study limitations, and risks may impact on different populations differently. 

Social / emotional impacts


Mental health/wellbeing

Research into digital technologies and adolescent mental health has shown mixed results. Some studies have found that moderate use of digital devices can have minimal impacts, or can even support wellbeing, but several hours per day can have a negative impact on mental health for young people. Along with duration of use, other factors can influence the impact of digital devices on mental health, including pre-existing mental health, the type of device, screen media content, gender, and the age of the young person. These factors may be more important than duration of use, and further research is needed to better understand these issues.

Social skills 

Digital technologies have been used selectively to support social skills for at risk children and young people. However, frequent and extended screen time has been associated with reduced ability to empathise, and more difficulty making friends. 'Many people are looking at the benefits of digital media in education, and not many are looking at the costs,' said Patricia Greenfield , a distinguished Professor of Psychology in the UCLA College and senior author of the study. 'Decreased sensitivity to emotional cues - losing the ability to understand the emotions of other people - is one of the costs. The displacement of in-person social interaction by screen interaction seems to be reducing social skills.' Understanding non-verbal communication is crucial, and is associated with personal, academic and social success. Non-verbal cues are much stronger when communicating face to face rather than digitally. Extensive use of digital communication can impact negatively on the development and mastery of social skills in younger children.​ Providing learning tasks that include collaborative on and off screen opportunities, and limiting screen time for young students may support the development of social skills.

Special populations

Specific and selective use of digital technologies has potential to support neurodiverse children, and to make learning accessible for students with special learning needs.

Children with ADHD and Autistic Spectrum Disorder (ASD) have been also found to be at higher risk of experiencing negative effects from screen time, and of developing internet and video gaming addictions (1-4). Consideration of these challenges is also needed, and the provision of non-digital homework may support young people and families with problematic internet use.


Cyberbullying within school hours

Cyberbullying and the increased risk of self-harm/suicide by victims are significant reasons why smartphone use in schools is being reassessed in other regions. New Zealand youth have recently been found to have among the highest cyberbullying rates in the world. Several websites and organisations can offer support if you have these concerns for your child, such as bullyingfreenz, or resource lists from the NZ police website.


Inappropriate content access

A range of services and strategies are provided to increased online safety and to reduce inappropriate and distracting content for children, when using digital devices at school in New Zealand. However despite protective services, both parents and teachers report that even primary school-aged children are accessing inappropriate and R-rated content during school hours. Kids can get around services with VPN's and many other means. To reduce risk of harm from inappropriate and distracting content, along with cybersafety services and education, younger students need to be supervised while online. 



The impact of viewing pornography for children can have both immediate and cumulative problems. Pornography exposure is thought to be shaping young people sexual attitudes and behaviours and redefining sexual norms. A New Zealand survey of 622 health providers, youth services, schools, therapists and whanau indicated an increase in youth presenting with genital injuries caused by young people re-enacting violent and aggressive pornographic scenes on each other. Most survey stakeholders indicated that porn has become a primary sex educator for young people, and were concerned about the messaging that often normalises sexual violence, poor understanding of consent, sexism and misogyny towards women and girls. Principals, teachers and counsellors raised concerns, giving many accounts of students viewing porn on personal or devices during school hours.


If you would like further information or support about early pornography exposure and how to support young people, The Light Project has excellent online resources.


Family conflict

Many families are experiencing conflict, tension, and disagreement in relation to screen use. Developing family media plans or talking to your doctor may help to find solutions that work for your family.


Data harvesting

Children’s privacy and data security can be threatened by data harvesting and surveillance, including through use of educational technologies. Data harvesting refers to the collection of information from every interaction a child has with an electronic device, such as grades, habits, disciplinary matters, attitudes, sociability and even location. Concerns have not only been expressed for students' privacy, but for their intellectual freedom, when every online thought and attitude is collected and analysed. Schools are advised to be aware of who can access student data, to convey this to families, and to consider student privacy before using digital products. Further government regulations have been recommended to support students' rights to privacy and confidentiality.

Analysis of 163 education technology products (Human Rights Watch, 2022) recommended for children’s learning during the COVID-19 pandemic found that 89% surveilled or could surveil children in educational settings or outside of school hours, in ways that infringed their rights.

UNESCO Global Education Monitoring Report 2023


While more research is needed, there is broad agreement in the scientific community that digital devices expose children to both opportunities and risks. Solutions are complex, and helping young people to develop healthy screen behaviours requires support from caregivers and policy makers. Within education settings, these risks indicate a need for balance and age-dependent guidance for screen use in schools. See ‘Recommendations’ for further information.

Educational impacts


Digital technologies are ubiquitous across the globe, and have been widely adopted in education. Students need to learn skills to navigate the digital world, and technologies present opportunities for learning beyond analogue methods. Digital technologies can provide access to education for remote learners and in emergency situations. See ‘What’s going well’ for more information on effective technology use in the classroom.


Along with opportunities for learning, digital technologies also present risks, not only to health/wellbeing from excessive use, but risks to privacy, equity and learning outcomes.

Educational outcomes

Studies have found mixed results when investigating the impact of digital devices on educational outcomes. There is limited high quality research, and much of the evidence supporting technology use has been identified as coming from ‘those trying to sell it.’ 


The results of large population-based studies show improvements in some areas of learning but not others, and a limit to the amount of device use that can achieve those improvements. See ‘Best outcomes’ for more information on how much device use achieves the best outcomes.


The age and stage of students also can impact the effectiveness of using digital technologies in the classroom, and older students may have more to gain. A United Nations Generally Assembly report has called for full discussions on the impacts of digitisation of education, including the age-appropriateness for introducing digital technologies into school, and what skills and competencies are needed before developing full digital competencies.


Engagement and Distraction

Student engagement is often cited as a benefit for using digital devices, particularly in primary schools. Some studies show improved engagement for children when learning online, but others do not, so results are mixed. Improved engagement with learning when using digital devices does not necessarily mean improved learning, so engagement needs to occur with effective methods and practises of teaching.

Studies have shown students spend significant portions of class time being distracted by their digital devices. New Zealand students are ranked 5th in the world for being distracted by digital technologies in class. Distraction is often ignored in research investigating engagement.


Distraction can occur not only with the immediate interruption, but by 'resumption errors' - errors in performance that occur for a period of time after an interruption. Device use has been shown not only to distract the user and reduce their comprehension and test performance, but also to distract and disadvantage those seated around them within visual range of their screen. 'Those around see the screen and attention is pulled...not just to note-taking but Facebook, Twitter, email and news,' (Dynarski, 2017).


Distractions can be limited by requiring devices to be put away when they are not being used for learning tasks, by teaching digital citizenship, setting clear expectations and supervising use for younger students. 



Multi-tasking, defined as the simultaneous use of more than one form of media, has been found to increase the time it takes to complete a task, to increase errors, and to reduce attention, despite student perception often being the opposite (5-8).


Research by Common Sense Media looking at 2600 children age 8 to18 years, found that half of teens are on social media while doing homework, 60% are texting, 76% are listening to music and more than half are watching TV.



Research has indicated that the physical process of forming letters when writing (which doesn’t become fluent until around age 10) is an important part of encoding letters and sounds, which impacts on the development of letter recognition and literacy. 'Keyboards cannot replicate the inherent cognitive and educational benefits that handwriting provides' (Mann et al, 2015). Studies have found that students have less understanding and retention of information when taking notes in class on a laptop compared to handwriting.


A large randomised trial by Carter et al (2016) found students who had laptops and devices removed from class performed significantly better in exams than those with both restricted and unrestricted access.


The stylus has been seen as a solution that allows young students to learn to write in a digital learning environment. A stylus can allow additional functions that handwriting cannot, and can augment learning for students with special needs. However, the stylus is 'yet to be perfected' and has not been broadly adopted.


Studies have looked into the differences between pen and paper writing versus pen-based interaction with devices. They note that writing with a stylus on glass does not provide the same experience as pen and paper. The smooth glass offers limited feedback, so users have to keep an 'eyes on the screen' approach to compensate for this. Users hold their hand differently on the screen compared to paper, which can lead to fatigue. Despite technology aimed at correcting the issue, 'unintended touch,' where the device detects additional touch points from the users can be a problem, as can latency (delay in mark making). Latency does not exist with pen and paper as the ink rolls out instantly. The inaccuracy of the stylus is a common frustration, with ink not being deposited where expected. Study participants have also reported using a stylus affected writing speed and size, and they made larger, straighter and seemingly more haphazard gestures when sketching. Users report higher frustration using a stylus compared to pen and paper, and note a preference for pen and paper interface.



Digital tools have been described as 'least helpful to students learning to read.' A New Zealand MOE study found that students who engage in digital tasks 'weekly or more' have lower enjoyment of reading. The more devices children have access to with e-reading capabilities, the lower their reading frequency. While 93% of Year 5 students use computers when learning to read in NZ (compared to an international average of 44%), this year group ranked last across English-speaking countries for reading.

Print and digital texts foster different styles of reading and different ways of thinking and doing research.

Studies have found students have less understanding and comprehension when reading long or complex text on devices when compared to paper as well as lower recall of information.


This is thought to be due to several processes. Scrolling is known to hamper the process of reading, by affecting the reader's spatial awareness of the text. 'A good spatial representation of the physical layout of a text supports good reading comprehension,' (Mangen et al, 2013). They note that computer readers are restricted to seeing and sensing only one page of the text at any given time. Therefore their overview of the overview of the organisation, structure, and flow of the text may be hampered.


Skim reading when online is also a common behaviour, including keyword spotting, browsing and scanning, and non-linear reading. Print reading takes longer, and students are more likely to reread. Understanding these differences can help older students to make the most of reading in print and online forms. Skimming and scanning is useful when researching and covering large amounts of information, so working online may be best suited to this type of task. Conversely, reading complex text in print for may help students to understand and remember more. Research has shown a correlation indicating people who frequently use electronic devices may have more trouble comprehending scientific text. The author questioned whether the way people read on e-devices encourages them only to pick up 'bits and pieces' of information, while the comprehension of scientific information requires a more holistic approach to reading where the reader incorporates the information in a relational and structured way. Multi-tasking and distraction when reading online can also affect concentration.

For information on how to use this knowledge of reading differences to teach improved deep reading and digital reading skills, go to 'What's going well in education.'


For further information and references on risks, go to 'Resources'.


References not included in hyperlinks:


1) Murray, A., Koronczai, B., Király, O., et al (2022). Autism, Problematic Internet Use and Gaming Disorder: A Systematic Review. Review Journal of Autism and Developmental Disorders, 9, 120–140.


2) Mazurek, M., & Englehart, C. (2015). Video Game Use in Boys With Autism Spectrum Disorder, ADHD, or Typical Development. Pediatrics, 132 (2): 260-266.


3) Weinstein, A,. & Weizman, A. (2012). Emerging Association Between Addictive Gaming and Attention-Deficit/Hyperactivity Disorder. Current Psychiatry Reports, 14 (5) 590-597.


4) Weinstein, A., Yaacov, Y., Manning, M., & Weizman, A. (2015). Internet addiction and attention deficit hyperactivity disorder among schoolchildren. Israel Medical Association Journal. 17 (12): 731-734.


5) American Psychological Association, (March 20th, 2006). Multitasking: Switching costs.


6) Moisala, M., Salmela, V., Salo, E., Carlson, S., Salonen, O., Lanka, K., Palmela-Aro, K., & Alho, K. (2016). Media multitasking is associated with distractibility and increased prefrontal activity in adolescents and young adults. Neuroimage, 1 (134): 113-121.


7) Ophir, E., Nass., & Wagner, A. (2009). Cognitive control in multitaskers.Proceedings of the National Academy of Sciences of the United States of America,106 (37): 15583–15587.


8) Wood, E., Zivcakova, P., Gentile, P., Archer, K., De Pasquale, D., & Nosko, A. (2011).Examining the impact of off-task multi-tasking with technology on real-time classroom learning. Computers & Education, 58 (1): 365-374.

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