The triple twenty rule for every computer user

Natasha Mohammed*, 26, used to experience extreme headaches whenever she used computer or any visual display units like smartphones or tablets.

Upon being advised by her mother, Ms Mohammed went for an eye-checkup. Although she went to see an optician who advised her to wear anti-reflective (AR) spectacles, Ms Mohammed never understood what she was really suffering from since the eye number for spectacle prescription were negative.

But she recalls how the optician was asking her questions relating to the use of computer.

Ms Mohammed, who is a journalist in one of the country’s media houses, says “Although the headache I used to experience decreased to a great deal since I started using anti-reflective spectacles for computer use, I was still unaware of the problem.” She decided to do something to find out what it was.

The digital eye strain every computer user faces

It was until when Ms Mohammed visited a local optometrist that she became aware that she was a patient of Computer Vision Syndrome (CVS), joining millions of other patients of the problem worldwide.

The American Optometric Association explains that CVS, also known as digital eye strain, describes a group of eye and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use.

According to the Association, many individuals experience eye discomfort and vision problems when viewing digital screens for extended periods. The level of discomfort, the Association reports, appears to increase with the amount of digital screen use.

Causes and symptoms

Describing the most common symptoms associated with the computer vision syndrome, Mr Mohamed Mkwazu, an optometrist at Msimbazi Eye Centre in Dar es Salaam explains that; eyestrain, headaches, blurred vision, dry eyes and neck and shoulder pain are the most reported symptoms of the problem.

“These symptoms may be caused by poor lighting, glare on a digital screen, improper viewing distances, poor sitting posture, uncorrected vision problems and a combination of these factors,” explains Mr Mkwazu.

How big is problem?

Explaining the magnitude of the problem, Mr Mkwazu says that although he does not know any local study carried out specifically about the problem, he still believes the problem is growing.

He says, “We diagnose at least three people with CVS per day at our center, most of them being those working in office and who have frequent contact with computer or other visual display units.”

Worldwide, data shows that up to 70 million workers are at risk for computer vision syndrome, and those numbers are only likely to grow.

“People who work in the office with air conditioners (AC) are more likely to get CVS,” says Mr Mkwazu adding, “ACs gets our eyes dry faster and at the same time you are staring at computer.”

Is it preventable?

Some important factors in preventing or reducing the symptoms of CVS have to do with the computer and how it is used.

This includes lighting conditions, chair comfort, location of reference materials, position of the monitor, and the use of rest breaks.

“Most people find it more comfortable to view a computer when the eyes are looking downward.

1. Eye level: Optimally, the computer screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen, and a distance of 20 to 28 inches from the eyes,” Mr Mkwazu explains

2. Reference materials: They should be located above the keyboard and below the monitor. If this is not possible, Mr Mkwazu advices, a document holder can be used beside the monitor.

“The goal is to position the documents so you do not need to move your head to look from the document to the screen.”

3. Lighting: A person is supposed to position the computer screen to avoid glare, particularly from overhead lighting or windows. Using blinds or drapes on windows and replaces the light bulbs in desk lamps with bulbs of lower wattage.

“If there is no way to minimize glare from light sources, consider using a screen glare filter. These filters decrease the amount of light reflected from the screen,” says Mr Mkwazu.

4. Sitting position: In terms of sitting position, Mr Mkwazu says chairs should be comfortably padded and should conform to the body. Chair height should be adjusted so the feet rest flat on the floor. If the chair has arms, they should be adjusted to provide arm support while typing. Wrists shouldn’t rest on the keyboard when typing.

20/20/20 rest rule

To prevent eyestrain, Mr Mkwazu recommends 20/20/20 rule, which entails every computer user to follow.

It means; Every 20 minutes, take a 20-second break and focus your eyes on something at least 20 feet away.

Mr Mkwazu adds that to minimize your chances of developing dry eye when using a computer, make an effort to blink frequently.

“Blinking keeps the front surface of your eye moist,” he says.

Balance diet can help

People who work in offices have been reported that they do not have time to eat well. This prevents them from having a balance diet with vitamins and other nutrients necessary to make their eyes healthy.

Medical experts hence recommend taking foods rich in Vitamin-A such as carrots , green vegetables and red peppers and those that contain Vitamin D such as in egg yolk.