Screen time
Nationally representative data of children and teens in the United States show that the daily average of screen time increases with age.
[7][8] TV and video games were once largest contributors to children's screen time, but the past decade has seen a shift towards smart phones and tablets.
Studies have shown that the blue wavelengths are closely correlated to those from sunlight, which is what helps the body keep in sync with the sunrise and sunset.
[21] Night-time use of screens is common for Americans ages 12–18: A 2018 nationally representative survey found that 70% use their mobile device within 30 minutes of going to sleep.
[24] Data suggests those who had spent more time on their screens were more likely to wake in the night from notifications on their phone, or experience disruptive sleep.
[29] Studies have shown that if the amount of screen time adolescents spend was limited, the likelihood of obesity can be reduced.
Sitting to watch television, playing computer games or surfing the Internet takes time away from physical activities which leads to an increased risk of weight gain.
[32] Additionally, one study showed that the increased use of video games and other forms of media consumption led to more back pain among Norwegian teens.
[33] It has been reported that screen time negatively affects health in children independently of their physical activity and eating habits.
[16] High amounts of screen time also can significantly affect a person's mental health, although some have called these findings into question.
With this added risk, lack of sleep plays a major role in a healthy mindset, and without proper rest, mental health can degrade at a higher rate.
[39] A study on Korean children aged 24–30 months old found that toddlers with 3 hours of TV viewing per day were three times as likely to experience a language delay.
Toddlers with higher TV time also scored lower on school readiness tests, which measured vocabulary, number knowledge, and classroom engagement.
This part of the brain usually thins as people mature but the accelerated decrease could potentially be linked to amounts spent on screens.
According to study published in November 2019, children who have a longer screen time, have slower brain development, what hurt "skills like imagery, mental control and self-regulation".
[44] Research results indicated children who had high amounts of screen time had delayed white matter development, decreased ability to rapidly name objects, and poorer literacy skills.
[49] In a study done by Muppalla et al. excessive use of screen time in adolescents is linked with triggering dopamine, which is a neurotransmitter that acts as a reward system in the brain.
[50] In a literature review done by Anderson et al. (2017), children who have extensive exposure to particularly violent media are at risk of developing aggressive behaviors and a desensitization towards violence.
[51] Children that spend an increased amount of time on screens have less opportunities to interact with adults and caregivers which reduces their language development.
When children are spending most of their time using tablets and screens there are less chances for them to interact with adults, like their parents, to expand their language skill set.
It has been shown that younger, preschool aged children and the amount of screen time they are exposed to has a negative effect on their language development.
When these children are spending 2 or more hours on their screens, tablets, TV's it is more likely for them to have a poor vocabulary and shows delays in when they are starting to speak.
Toddlers after the age of 18 months can be exposed to high-quality programming such as Sesame Street or PBS that provide educational television.
[37] Research shows that children who lack guidance from their mothers are more likely to overuse screen time and also to struggle academically.
On the other hand, those who only consumed violent media or leisurely video games on school nights, showed a negative associated with academic achievement.
[58] Studies show nature-inspired activities simultaneously decrease for youth in financially stabilized countries with mental health issues increasing, drawing a connection to higher screen time levels.
[59] However, the higher the count in activities spent experiencing the outdoors produced positive results in mental health among adolescents.
For example, breaking up continuous blocks of screen time usage by stretching, maintaining good posture, and intermittently focusing on a distant object for 20 seconds.
