Most of us can no longer imagine a life without a smartphone. And we can spend hours in front of a screen without even realising. But how much screen time is actually safe? And what can we do to avoid exceeding this time?
Whether at work or home: screens – from tablets, computers to mobile phones – have become an integral part of our daily lives. We now read the news online, connect with friends and loved ones through social media and apps, and stream movies online – all of which involves looking at a screen. At present, teenagers spend an average of 3 hours and 47 minutes on their phones every day. This doesn’t include any additional time spent in front of a TV or computer.
One of the more common effects of spending long hours in front of a screen every day is having tired eyes and tense shoulders by the end of the day. But the consequences of excessive screen time can also be a lot more serious than that.
Chatting or working on a device always involves either sitting in front of a computer, or sitting or lying on the bed or sofa – all of which involves very little physical activity. A lack of physical activity can lead to tension in the body, circulation and back problems.
In addition to affecting our bodies, too much time spent in front of a screen can also have a detrimental effect on our mental health. Young people and children’s mental health in particular seems to suffer when digital device usage becomes a regular feature.
Humans blink about 10 to 15 times a minute and, every time the eyelid comes down, it moistens the surface of the eye with tear fluid. This process is very important for the health of our eyes. This is because tear fluid contains antimicrobial substances and hence protects the cornea from infection. However, when we are staring intently at a screen, we often forget to blink. This lack of blinking is what gives rise to computer vision syndrome, the effects of which are:
As well as staring at a screen, the blue light emitted by phones, TVs, tablets and computers is also very detrimental to our eyes’ health. Research has shown that large amounts of blue light entering the cornea unhindered can lead to the macula becoming inflamed (macular oedema). This can cause macular degeneration, which, in turn, will cause irreversible damage to the most important part of the retina and permanent loss of sharp vision.
Tips for protecting your eyes from excessive blue light:
It is particularly important to make sure that children do not spend too much time in front of a screen. The light emitted by screens actually stimulates eye development, which causes eyes to become longer. This can also lead to short-sightedness. However, excessive screen time also leads to less physical activity, which is very important for children’s development. For this reason, the WHO recommends that children under the age of two should not spend any time whatsoever in front of screens. From the age of two to four, the maximum recommended time is one hour. The EU European Safe Online Initiative has set out the following guidelines:
Other things parents can do
Jovana Stojanovic (pharmacist, MSc pharm. sc. ETH) works for Helsana health consultation. She supports customers on questions to do with health, illness and prevention. Jovana Stojanovic provided the editorial team with advice and input for this article.