By Dr Joy Chan, Medical Director and Senior Consultant Ophthalmologist, International Eye Cataract Retina Centre at Mount Elizabeth Medical Centre and Farrer Park Medical Centre, Singapore
Most of us spend the better part of our lives at work, and for a large proportion of us, time at work is time spent at a desk facing a computer. This month, we bring awareness to eye conditions that can arise from prolonged near work.
WHAT IS COMPUTER VISION SYNDROME?
Computer vision syndrome, also known as digital eye strain, describes a group of eye and vision-related problems that result from prolonged computer, tablet, e-reader and handphone use. Many individuals experience eye discomfort and vision problems when viewing digital screens for extended periods. The level of discomfort appears to increase with the amount of digital screen use.
Computer vision syndrome is associated with eye strain after long periods of computer use
SYMPTOMS OF COMPUTER VISION SYNDROME
The most common symptoms associated with computer vision syndrome are:
- eye strain
- blurred vision
- dry eye
- neck and shoulder pain
These symptoms may be caused by:
- poor lighting
- glare on a digital screen
- improper viewing distances
- poor seating posture
- uncorrected vision problems or a combination of these factors
CAUSES OF COMPUTER VISION SYNDROME
Viewing content off a digital screen is often harder than viewing printed content. This is because letters and images on digital screens are usually less precisely or sharply defined than printed content. In addition, contrast between background and content is usually reduced on screen. The presence of glare and reflections on the screen may also make viewing on screen content more difficult than print.
Viewing distances and angles for printed and on screen content also differ. As a result of this, one often has to focus and refocus at different distances and angles while working long hours at a desk.
In addition, the presence of even minor eye conditions can significantly affect the comfort and performance of a user of digital devices. Uncorrected or under-corrected eye problems such as refractive errors, dry eye and blepharitis can be major contributing factors to the development of computer vision syndrome.
Headache after prolonged computer work is a common symptom of computer vision syndrome
DIAGNOSIS OF COMPUTER VISION SYNDROME
Computer vision syndrome can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on visual requirements at the computer or digital device working distance, may include:
- Patient historyto determine any symptoms the patient is experiencing and the presence of any general health problems, medications taken, or environmental factors that may be contributing to the symptoms related to computer use.
- Visual acuity measurementsto assess the extent to which vision may be affected.
- A subjective refractionto determine the appropriate lens power needed to compensate for any refractive errors (eg, short-sightedness, long-sightedness or astigmatism).
- A dilated retinal examination to exclude any other eye problems that may impair vision or contribute to eye fatigue.
MANAGEMENT OF COMPUTER VISION SYNDROME
Treatment of this condition involves correcting any refractive errors your eyes may have, and optimising your work space to reduce sources of fatigue.
In some cases, individuals who do not require the use of spectacles for other daily activities may benefit from spectacles prescribed specifically for computer use. In addition, persons already wearing spectacles may find their current prescription does not provide optimal vision for viewing a computer. Spectacles or contact lenses prescribed for general use may not be adequate for computer work. Lenses prescribed to meet the unique visual demands of computer viewing may be needed.
Other helpful measures include:
- Location of computer screen– Most people find it more comfortable to view a computer when the eyes are looking slightly downward. Optimally, the computer screen should be 15 to 20 degrees below eye level (about 10 to 15 cm) as measured from the centre of the screen and 50-70 cm from the eyes.
- Reference materials– These materials should be located above the keyboard and below the monitor. If this is not possible, 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.
- Lighting– Position the computer screen to avoid glare, particularly from overhead lighting or windows. Use blinds or drapes on windows and replace the light bulbs in desk lamps with bulbs of lower wattage.
- Anti-glare screens– 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.
- Seating position– Chairs should be comfortably padded and conform to the body. Chair height should be adjusted so your feet rest flat on the floor. If your chair has arms, they should be adjusted to provide arm support while you are typing. Your wrists shouldn’t rest on the keyboard when typing.
- Rest breaks– To prevent eye strain, try to rest your eyes when using the computer for long periods. Rest your eyes for 15 minutes after two hours of continuous computer use. Also, for every 20 minutes of computer viewing, look into the distance (20 feet or beyond) for 20 seconds to allow your eyes a chance to refocus (the “20-20-20 rule”).
- Blinking– 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. Frequent use of eye lubricants may be helpful too.
Regular eye examinations and good eye habits can help reduce computer vision syndrome. It is important to schedule an eye examination to help diagnose and treat eye conditions that may contribute to computer vision syndrome, to make your time at the workplace less stressful for your eyes.