Blog

Is Too Much Screen Time Bad for Kids?

Published by Auckland Eye on Tuesday, 04 Dec 2018
109_2_lrgsize

Children and technology are practically inseparable these days. However, as children spend more time glued to their screens, there is an increasing concern about the potential harm to their visual development. Although the long-term effects of screen time are currently unknown,  excessive screen time can take a toll on children's health, including how their eyes may feel. Children who spend multiple hours staring at digital devices without taking breaks are at risk of developing vision and sleep-related problems including:

 

  • Eye Fatigue

Muscles around the eye, like any others, can get tired from continued use. As a result, children, as well as adults) can often experience concentration difficulties and headaches centred around the temple and eyes after focusing on a screen for extended periods of time. Children may also use screen devices where lighting is less than ideal, causing fatigue from squinting.

  • Dry Eyes

To keep our eyes healthy and lubricated, we normally blink about 10 to 15 times per minute. However, studies show that people tend to blink significantly less when concentrating on digital screens. Additionally, computer and phone use often cause more incomplete blinks, so the tear film is not spread across the entire cornea causing the eyes to become dry and irritated. Blinking is important because with every blink, your eyelids spread a fresh layer of tears across the surface of your eyes to keep them moist, comfortable and healthy. Therefore, often when children are immerged in their computer games or watching TV, their eyes can become dry and irritated after a period of time.

Desktop computer and television use can be especially tough on children's eyes. This is because since these items  are usually situated higher up in their visual field than a book, for example, as a result, the upper eyelids tend to be open wider which can speed up the evaporation rate of the eye's tear film.

  • Blurry Vision

Gazing at the same distance for an extended time can cause the eye's focusing system to spasm or temporarily "lock up." This condition, called an 'accommodation spasm', is when the ciliary muscles temporarily cannot relax,  causing the child's vision to blur when he or she looks away from the screen or when attempting to view objects from a distance.

  • Poor Sleep

The LED screen of computers and other digital devices emit a broad spectrum of visible light. Most of the light rays are harmless, but a portion of the light emitted by these screens is relatively high-energy vision light called "blue light", which plays an important role in regulating the body's circadian rhythm (our body's internal clock). It is believed that blue light from screens has a similar effect to caffeine and can affect your sleep cycle.

Blue light affects levels of the sleep-inducing hormone melatonin more than any other wavelength of light. Studies have shown that too much exposure to blue light from digital devices can, therefore, disrupt a person's normal sleep/wake cycle, which can have serious health consequences.

For this reason, children (and adults) who look at their phones or other digital screens shortly before going to bed can experience sleep disruption and can find it more difficult to fall asleep at a normal time. Sleep disruption can be especially problematic for children, leading to daytime drowsiness and poor performance in school.

  • Myopia

Vision researchers believe increased screen time among children is a significant risk factor for the development and progression of myopia (nearsightedness). Since 1971, the incidence of nearsightedness in the US has nearly doubled, to 42 percent. In Asia, up to 90 percent of teenagers and adults are nearsighted. Due to these alarming statistics, with the rising prevalence of nearsightedness amongst the 'digitally native' youth worldwide in the last few decades, researchers are concerned about the long-term effects that digital devices may be having on the younger generations' vision.

A new study featured in Ophthalmology, the journal of the American Academy of Ophthalmology, states that at least part of the worldwide increase in nearsightedness might otherwise be related to near work activities; not just screens but also traditional books. The study also highlights that more time playing outside, especially in early childhood, may slow the progression of nearsightedness and result in healthier vision development in children.  

In conclusion, it remains unclear whether the rise in nearsightedness is a result of the younger generations focusing on smartphones and staring at other digital devices all the time, or if it is caused by the light from digital devices interacting with children's' circadian rhythms and influencing eye growth. All of these theories are simply hypothesised and yet to be further researched.

 

Tips to Help Protect Your Child’s Eyes and Health With Digital Device Usage

With the rise of laptops and technology playing a significant role in children's lives, whether for educational purposes or just fun, it's unrealistic to think that children will stop using modern technology altogether. Fortunately, there are some easy things you can do to decrease your child's risk of eye and vision problems from prolonged use of computers and digital devices. Here are our 12 tips:

  • Remind your child when to take a break or when screen-time is up. To do this you can set a kitchen timer or a smart device timer.
  • Alternate reading an e-book with a real book and encourage kids to look up and out the window every two chapters.
  • Make sure digital devices are turned off at least an hour before bedtime.
  • Encourage frequent visual breaks. For example, after completing a level in a video game, tell your child to look out the window for 20 seconds each time.
  • Pre-mark books with a paperclip every few chapters to remind your child to look up. On an e-book, use the “bookmark” function for the same effect.
  • Establish media free times and encourage your kids to go outdoors – regular play and exercise can help prevent or reduce the development of myopia.
  • Teach your child to adjust the brightness and contrast of their digital devices so that it feels comfortable and to use  night settings. Using night settings, may help your child sleep by reducing the amount of blue light given off by the screen during night-time hours.
  • Encourage your child to use good posture when using a computer and when reading.
  • Protect their eyes from blue light and buy glasses that filter blue light from digital screens for your child to wear while using digital devices.
  • Remind your child to blink when watching a screen.
  • Encourage your child to hold digital media farther away from his/her face, 18 to 24 inches is ideal.
  • Book your child in for a sight test every two years, from the age of three, or more often if your eye specialist recommends it.

 

 

How much screen time is too much?

Although children and technology are the future, many parents these days often question "how much is too much screen time?" To answer this simply, according to the American Academy of Ophthalmology, it is recommended that parents limit screen time for kids to a maximum of just two hours per day. For younger children, age 2 to 5, the recommended limit is one hour per day.

On the other hand, to more realistically answer this question, we believe that there is no magic number that is universally "just right" for every family. What's more important is the quality of children's media (making sure that it is age-appropriate), how it fits into your family's lifestyle, ensuring your children have plenty of periods of physical activity and ensuring they develop healthy media usage habits. The reality is that most families will go through periods of heavy and light media use, but, so long as there's a healthy balance, with screen-time kept in moderation, kids should be just fine. Overall, taking these simple measures mentioned above can go a long way toward keeping your tech-savvy child's eyes healthy for years to come.

Auckland Eye - New Zealand Centre of Excellence for Eye Care