What is Computer Vision Syndrome?
Computers have equalled the telephone in becoming the most indispensable piece of office equipment. Because computer use is such a visually demanding task,
vision problems and symptoms have become very common in today’s workplace. Most studies indicate that computer operators, who view their Video Display
Terminals (VDTs), report more eye-related problems than non-VDT office workers.
What are the causes of this eye disorder?
Image drawn by computer
Anyone who spends two or more hours a day working on a computer is at risk for developing CVS. The reason is simple: human vision is not suited for staring
at a computer screen. Computer images are made up of tiny dots, known as pixels. Since eye cannot focus on them, one must constantly refocus to keep images
sharp. Eventually, this results in repetitive stress of the eye muscles.
Image seen by eye by constant re-focusing
There are other key differences between looking at a printed page and a computer screen.
• A monitor is a dynamic signal, in that the screen is constantly being ‘redrawn’
• A monitor creates images on the basis of varying light intensity through a fixed set of red, green, and blue points. This results in less distinct edges,
and lower contrast
• The illumination profile of points on a monitor is not sharp (bright to dark), but is somewhat rounded, again reducing contrast
What are the signs and symptoms?
list of 12 items
• Blurred vision
• Burning or red eyes
• Slow refocusing
• Sore or tired eyes
• Double vision
• Light Sensitivity
• Dry eyes
• Back pain
• Neck pain
• Colour distortion
How is it diagnosed?
The diagnosis is essentially clinical. The Eye-Computer Ergonomic Evaluation (Eye-CEE) System for Computer Users® consists of an on-line questionnaire and
vision tests which can determine if the symptoms are related to your vision or to your environment. The program produces reports that can be taken to a
doctor, so that they can do a more effective examination of your vision. It is shown to be the most effective way of determining computer-related visual
Are there any precautionary measures?
There are certain preventive measures which can be taken to reduce eyestrain while working at a computer. These are:
• Position the monitor 20 to 26 inches away from your eyes
• Arrange light sources to minimize glare
• Blink more often to moisturise your eyes
• Take frequent breaks from your computer
• Exercise even when sitting
Also consider getting a PC Magni-Viewer. Essentially a lens that is placed in front of the computer screen, this device creates a larger, more distant image that demands less focusing power, reducing the eye strain associated with computer use.