VDT Syndrome

Using everyday devices such as computers and smartphones for long periods of time has led to an increase in symptoms such as eye strain, headaches, eye pain and blurred vision, stiff neck and shoulders, and dry eyes. These are known as VDT syndrome and IT eye disease. Recently, this condition has become more common due to the increase in remote work opportunities and children spending long periods of time playing smartphone games.
This article describes following topics.

・Reasons why VDT syndrome occurs
・Treatment and prevention methods
・What children should pay special attention to

VDT (Visual Display Terminal) Syndrome is a condition caused by looking at computer or smartphone screens for long periods of time, which can lead to eye and physical fatigue and mental disorders. It is also known as IT (information technology) eye disease.
The household ownership rate of smartphones and tablet devices, which was less than 10% around 2010, has rapidly increased over the past decade, and the latest statistics show that tablets account for 40% of households and smartphones for just under 90%.
In recent years, VDTs have become ubiquitous around us. (Source: 2021 White Paper on Information and Communications)

Furthermore, with the spread of social media and video sites and the establishment of remote work, opportunities to look at displays such as computers, smartphones and tablets have increased, and the number of people suffering from VDT syndrome, such as eye fatigue and headaches, is rapidly increasing.

If you experience the following symptoms while using a computer or smartphone for long periods of time, you may have VDT syndrome.

Eye Symptoms

The main visual symptoms of VDT syndrome are:

・Dry eye (dryness of the eye)
・Eye pain
・Eye fatigue
・Blurred vision
・Redness
・Eye drowsiness
・Decreased vision
・Blurred vision

Staring at a screen continuously without taking sufficient breaks can cause a variety of problems to appear all at once.

Physical symptoms

Looking at a screen for a long time can cause muscle pain and stiffness due to continued tension. It is important to pay attention to symptoms such as numbness and fatigue, as well as neck and shoulder pain.

・Headache
・Stiff neck and shoulders
・Dizziness
・Shoulder, arm, or back pain
・Numbness in the hands and fingers
・Weakness in legs and feet

Mental and neurological symptoms

VDT syndrome is known to adversely affect mental health.

・Anxiety
・Irritability
・Anorexia
・Depression
・Inability to sleep well

Experiencing these symptoms can make you feel even more anxious and irritable, creating a vicious cycle of stress.

Below we explain why looking at a screen for long periods of time can cause various symptoms of VDT syndrome.

Due to overuse of the eyes

The eye has the ability to adjust the thickness of the lens to focus on what you want to see. The ciliary muscle is responsible for adjusting the thickness of the lens. When you look at something far away, the lens relaxes and becomes thinner. When you look at something close up, the lens bulges. Looking at a VDT screen (close to your eyes) for a long period of time causes the ciliary muscle to remain tense, resulting in eye fatigue.

Due to becoming eyes dry

If you spend more time using your smartphone or computer and blink less, tears will not reach the surface of your eyes sufficiently. As a result, your eyes will become dry and you will fall into a lifestyle-related disease called dry eye. It is important to be careful as this can lead to various eye problems.
Click here for an explanation of “dry eye”.

Due to damage to the cornea

The corneal epithelium, which is the outermost layer of the cornea, protects the eye. When tears decrease and the eyes become dry, it becomes difficult to remove foreign objects from the surface of the eye, and blinking can damage the surface of the eye. In other words, repeated daily VDT work can gradually damage the cornea.

Eye drops are used to treat VDT syndrome. The aim is to alleviate relive eye fatigue and prevent eye dryness.In addition to eye fatigue, patients with severe muscle tension in the neck and shoulders may also be treated with medications to relieve muscle tension.
Another treatment is to take care of your eyes by using glasses or contact lenses suitable for computer work.

Even people who work a lot on computers daily can expect to prevent VDT syndrome to a certain extent if they take measures such as arranging their work environment appropriately and taking frequent breaks.
Please refer to the figure below to adjust your work environment.

Source: “Guidelines for Occupational Health Management in Information Equipment Work”

Creating an Appropriate Working Environment

＜Brightness＞

Adjust lighting to minimize the difference between “light” and “dark” in the room.
Put curtains or blinds on windows in rooms that get a lot of sunlight.

< Computers and tablets＞

Adjust the screen brightness and contrast to make it easier to see.
The screen should be positioned 40 cm away from your eyes so that your eyes are facing slightly downward.
Use an external keyboard and mouse so that they can be moved.
Place the display in a position that reduces reflections. Anti-reflective displays are also effective.

＜Chairs and desks＞

Your desk should be large enough to accommodate your equipment and documents, and at a comfortable height for working.
The desk needs to be wide enough so that you can move your legs under it.
Chairs should be stable and easy to move. Seat height and backrest should be adjustable.
Sit deeply, resting against the back of the chair and keeping the entire soles of the feet in contact with the floor.

Dryness in the room (air in the room) is another cause of eye problems. Long-time VDT work in an air-conditioned room can easily dry out the eyes, so it’s recommended to humidify the room.

Take appropriate breaks

In order to reduce the mental and physical burden, it is effective to limit VDT work to one hour continuously and take a 10–15-minute break between tasks. It is also recommended to take a short break of 1-2 minutes in the middle of work.

Things to keep in mind daily

When you’re not working, it’s a good idea to take up exercises such as gymnastics and stretching to relieve tension. Light stretching during breaks is effective in preventing VDT syndrome. It’s recommended to incorporate simple exercises that can be easily performed while sitting, such as neck and shoulder stretches.
Wearing the wrong glasses or contact lenses while working can make you feel tired. Get a prescription from an ophthalmologist and use lenses that suit you.
If you experience severe fatigue or vision problems, see an ophthalmologist as soon as possible.

Many children say they “like video games.” Recently, it seems that some children enjoy playing games not only on video game consoles, but also on smartphones and tablets.
However, long-time exposure to screens can cause eye fatigue, stiff shoulders, headaches, and other symptoms, even in children.
You should also be careful of “smartphone esotropia,” a condition in which you see double when you look at a smartphone screen close to your eyes for a long period of time.

Be careful not to play games for more than an hour

The number of children with myopia is increasing both nationally and globally, especially among children aged 6 to 15, and it is believed that playing video games for long periods of time each day increases the chances of developing myopia.
*For data on children with myopia, see the article “Myopia.”

About 30 minutes of gaming time is acceptable, but if it exceeds an hour, you should be careful. After playing video games, make sure to rest your eyes by looking into the distance.

Spend more time outdoors.

A simple and sure way to help prevent myopia in children is to play outdoors and get plenty of sunlight. Spending two hours a day outdoors has been shown to help prevent/delay the onset of myopia. Outdoor play relaxes the body and relieves many eye symptoms. There is also evidence that spending around two hours a day outdoors can help slow the progression of myopia.

How is VDT syndrome treated?

VDT syndrome can be treated with eye drops and oral medications that relieve muscle tension. The use of spectacles or contact lenses suitable for computer work is also effective. Creating an appropriate work environment, taking breaks regularly and exercising in between tasks can help prevent the condition.

Is it true that the autonomic nervous system is disturbed by VDT syndrome?

It’s important to note that long-time VDT work and overuse of the eyes can also stress the brain and cause disturbances in the autonomic nervous system.
As a result, various mental symptoms may occur, including insomnia, loss of appetite, overeating, dizziness, anxiety, and depression.