A young woman in a cat costume at the computer game festival 'DreamHack' in Leipzig, Germany, 22 January 2016. [Photo/IC]

As the use of digital devices is becoming more common, so are many conditions associated with their increased use. That is why, especially given the excessive use of digital devices during vacations, youngsters should be particularly careful. This applies to all kinds of digital devices, including TV and gaming systems, tablets and computers, and smartphones.

An estimated 28 percent of the people in the United States spend 10 or more hours a day in front of digital devices, and 65 percent spend three to nine hours doing the same. The 2015 Visio Council report on digital eyestrain says more than 90 percent of American adults use digital devices for at least two hours a day. And more than 60 million children worldwide likely use digital devices for several hours a day, which doesn't include TV time or gaming systems.

China is now home to the largest number of cellphone and Internet users in the world. Digital activity has become an integral part of Chinese life, and instant messaging is the main form of online communication.

It is, therefore, necessary for them to know that exposure to the screens in digital devices increases the risk of digital eyestrain, also known as computer vision syndrome. Digital eyestrain is a group of eye- and vision-related problems caused by the frequent use of computers and other digital devices. Many experts say it is not the use of these devices that causes problems but how we use them.

Among the symptoms exhibited by digital eyestrain sufferers are redness of the eyes, dryness due to decreased blinking, blurry vision due to screen glare - particularly from short distances - increased sensitivity to light, insomnia and headache. In many cases, digital eyestrain is a combination of all these symptoms. While some people don't experience any symptoms even after frequent use of digital devices, the condition could be disabling for others.

A kind of artificial light, also known as high-energy visible light or blue-violet light, which was typically used in fluorescent displays, can now be found in smartphones, tablets, computer screens, flat screen TV devices, CFL light bulbs as well as street lamps. The frequent use of digital screens can have damaging effects over time, and they have been associated with macular degeneration and reduced production of melatonin potentially resulting in reduced and altered sleep patterns.

Existing eye conditions can play an important role in the development of eyestrain. It has been shown that eye conditions such as myopia, astigmatism and presbyopia - a condition that typically occurs in middle and old age - are frequently associated with digital eyestrain. That is why it is very important to make sure that children in particular undergo frequent and complete eye checkups.

There are several ways to help children develop good habits while using digital devices, such as investing in computer eyewear that prevent digital eyestrain and block blue light, encouraging children to take breaks when using digital devices, and explaining to them the risks of long exposure to smartphones and other similar devices.

In addition, it is important to create a proper home atmosphere for children to work on digital devices such as chairs that help the users to maintain correct postures, to take frequent breaks when working on computers, to use specific lenses designed to minimize computer-related eyestrain, to use eye drops to help prevent dry eyes, to adjust the distance to the computer monitor and to use glare-reducing screens.

The importance of following the above mentioned measures is that we are not only preventing eye-related problems now, but also ensuring that our children will have a healthier future.

The author is an international public health consultant.