All of this symptoms can be triggered in your place of work and the collection of all of these health issued is referred to as CVS
In order to avoid the numerous symptoms of Computer Vision Syndrome (CVS), it is important to ensure that your computer is properly positioned since the use of computers is almost unavoidable.Wrong body posture, fatigue, neck and shoulder pain are inevitable consequences of a wrongly positioned computer screen or system. The question is are your office systems properly fixed?
The Viewing angle; it refers to the centre of the computer screen and
Viewing angle: The image below shows a normal line of sight.Your line of sight is towards the centre of your computer screen. Ensure you get it right, because a poor angle can result to neck and shoulders discomfort.
- The extent of downwards movement of the line of sight may range from about 15 degrees to almost 30 degrees.
- People engaged in visually demanding tasks limit their downward eye movements to about 30 degrees (half of the whole available range of 60 degree}.
- Looking upwards (above the horizontal) is tiring.
- Looking downwards, (lower than 15 degrees below the horizontal) is not tiring
- Do not place your monitor on top of the systems unit or CPU as locally called. This can cause musculoskeletal problems in the neck and shoulder area because the monitor will be too high.
- If you use a workstation with good height adjustment for the desk and chair, the monitor should be placed at the same level as the keyboard.
- Your monitor is too high when it is above the horizontal level and too low when it is below an acceptable visual zone.
- The consequence of a monitor which is too high is worse than that caused by an overly low monitor
- For 17″, 19″ or larger monitors or one with a “portrait orientation” ensure that the top of the screen is not higher than the operator’s eyes
- Focusing on far distances does not cause eyestrain, but when you focus on close objects at close distances, a muscular effort is required and used. This is what causes strain to the eyes.
- Accommodation and convergence are the two main functions which governs the viewing of objects at closer distances.
- Accommodation is the automatic adjustment of the eye for focusing on near objects. The eyes achieve this by changing the convexity (or shape) of the lenses.
- Convergence is the automatic inward (toward the nose) turn of the eyes when viewing close objects.
- But like a rule of thumb “the shorter the viewing distance, the greater the muscular effort required for accommodation and convergence. This increases the risk for eye discomfort
- The viewing range 40 cm to 70 cm (about 15 – 27 in.) provides visual comfort for majority of computer users.
- The right viewing distance is the one at which you can easily read on the screen without experiencing eyestrain.
- A higher viewing distance reduces your risk of eyestrain, however it can make it more difficult to resolve finer images or characters displayed on the computer screen.
- Whenever the recommended viewing distance is too great for you to see images clearly it is better to increase the font size or images than to force a shorter viewing distance.