Visual Display Units - Viewing Computer Monitors from a Safe Distance

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Viewing the VDU (Visual Display Unit)

Although there isn’t any solid evidence presented by experts that would prove that intensive use of Visual Display Units (VDUs) damages the eyes, we often hear people complaining about eye problem of one type or the other. There are many ways that VDUs can cause eye-strain and headaches; these include insufficient lightning, infrequent rest periods, or incorrect positioning of the VDU.

There are also some links between VDU technologies and eye-strain, but this technology is improving very fast. The technology used in the latest VDUs are comparatively less dangerous to eyes as they offer both better display quality and comfort for eyes. Among these technologies are LCD and Plasma with the most recent one being Plasma. These VDU technologies offer excellent picture quality and are ’eye-friendly’ because these do not emit any form of dangerous rays. One of earliest VDU technologies was the CRT (Cathode Ray Tube). This technology is receives a lot of criticism by the bulk of its users, because it emits harmful cathode rays that can cause eye problems.

With so many types of VDUs available to us, it would be advisable for computer users, especially computer geeks, to buy a display that best suits the eyes, such as LCD or Plasma. But it’s also important to take other precautions when setting up your monitor display. Some people use computers for 8 or more hours everyday, and unless the VDU used is viewed from the safe distance, it will certainly cause eye-strain, and possibly headaches.

The Safe Distance

So, for computer users, what is the safest viewing distance to use with your VDU?

A typist, with a VDU about 30 inches from his eyes, feels comfortable. However, ergonomics suggests the most comfortable distance for eyes is between 21 and 27 inches. The experts say that closer objects cause greater strains on the eyes’ muscles.

It is obvious that if we can’t read something on screen clearly, we need to make some adjustment. We can have either of two situations:

  1. The font or screen size can not be further increased/decreased. In this case, only thing we can do is increase or decrease the distance of the VDU from our eyes until we can see more clearly.

  2. The font/screen can be increased or decreased. Now the first step that should be taken is to check distance between our eyes and the VDU. If there is already a good gap, we may then consider changing the font or the screen resolution until the view becomes clear.

VDUs can easily cause short-sightedness or eyestrain due to the unnecessary closeness with which they are commonly viewed. The further out the VDU is, the more relaxed the eyes will be.

Some might think that they cannot place the VDU at the correct distance because the cables of the keyboard or mouse are not long enough. In this case, wireless computer devices such as Wi-Fi or Bluetooth keyboards and mice can be used that would allow the user to have more room and place at the right distance.


Experts recommend that computer users view their VDUs from a safe distance, which is between 21 and 27 inches. Any closer than that and you run the risk of serious eye-strain, headaches, and other problems that can result from overuse of the eyes. Remember, the closer the monitor is, the harder the eyes will have to work!