Thought Bytes...
February 2003

Monitors: is bigger better?

The workplace has come a long way since the 14" monitors that we started with 15 years ago. About 10 years ago, a 17" monitor was considered a luxury. Now we commonly see 19", 20", even 22" screens. But, do we need bigger screens to do the job better?

People claim that they can have more information on the screen - more windows open - so that they can cross reference information better. This may be so for people who truly need multiple windows, but most workers only look at one window at a time. For example, while writing this article, I will only be looking at the Outlook window for about 30 minutes. There may be other programs running (i.e. accounting software, word processing programs, etc.) but I don't need to look at them for the duration of the task at hand.

With CRT (cathode ray tube) monitors, larger screens also mean more depth to the device. Some 17" CRT monitors are 24" deep. At some work stations, this has required the monitor to overlap into the keyboard space. The worker must then sit back from the keyboard in an effort to find a comfortable visual distance. The consequence is that the worker then has to reach forward to use the keyboard. Unless the desk has a corner section for the computer, large screens are not advised.

There is also the issue of visual accommodation. Larger screens would allow the character size to be larger when the resolution settings are the same as a smaller screen. However, the proximity of the screen to the keyboard and eyes (because of the greater depth) encourages workers to increase the resolution which decreases the character size. This doesn't really increase eye comfort, because the eyes are still continuously focusing at an object which is too close for most people. And, because the eyes have very small, weak muscles (that are heavily overused) neck muscles get overworked to reorient the head so that the eyes can scan over the surface of the screen.

The larger the screen is, the further it should be placed from the eyes. This allows the eyes to see the whole screen without requiring neck movements to allow the head to follow the eyes. Again, the depth of the monitor restricts the ability to place the screen at the correct distance.

The new LCD (liquid crystal display) monitors are certainly more portable and flexible and can be placed at an appropriate distance from the eyes. The small foot print of the monitor allows placement toward the back of the desk so that the whole screen can be viewed without significant head and neck movements and minimize the need to reach forward to the keyboard. For workers using dual monitors, this is essential. While the cost is still prohibitive for some of the larger screens, a 17-19" monitor will be sufficient for most workers.

Readers respond to the issue of LCD monitors:

"Something to consider about the LCD monitors is that the image is not as clear and is not clear from different angles/heights/distances (unlike a CRT)."

To be quite honest, I have found that the image is quite good, but the LCD screens that my clients use are usually high end products.

So, I did a bit of investigating... My computer guy, Mitchell Franczuk at CompuSmart, told me that while the technology is continuously improving and getting cheaper, you definitely get what you pay for with the LCD screens. But the screen may not be the problem. You could have a great quality screen, but if you don't have a top of the line video card in your computer, the image quality will still be poor.

The reader is right about the issue of the clarity from angles, heights and distances. For single users of the screen though, angles should not be an issue as the screen can be located directly in front of the computer user. When the screen must be viewed by more than one person at a time, the angles may present a concern. This only serves to emphasize the need to be able to position the monitor appropriately. For multiple users, this will mean ensuring that the monitor is on a flexible height, distance and angle arm. The LCD screens do have the distinct advantage over CRT screens in the lack of reflections though because they do not have a glass front, which improves clarity.

The last point that I want to mention about LCD screens is cleaning them. Mitchell warned me that no chemicals should be used on LCD screens to clean them. He recommended using a microfibre cloth which has been dampened slightly with a spray bottle with water. Chemicals (other than being respiratory irritants to many workers) may damage the membrane of the screen.

More response to the issue of LCD monitors:

At a recent Ergonomic Products trade show, I encountered a retailer who thought he had heard some concern about the use of LCD screens from an optometric practitioners society. As you may have gathered from past issues of Working Well, I am a proponent of the use of LCD screens because they have a small foot print, minimal reflected glare, no flicker and great resolution (with a good video card). To clarify the issue, I contacted my own optometrist who happens to be the past president of the World Council of Optometry:

"Hi Sharon,

I checked with both the Canadian Association of Optometrists and the US guru on computer terminal research at Ohio State University School of Optometry (advises the AOA). Neither of them had anything negative to report on LCD screens. In fact, the only comment was that they probably were superior because of less flicker and a smaller footprint on the desk (pretty much exactly what your position is.) So I would suspect that the information you got was the creation of an over-zealous sales person. Certainly there is no strong feeling against LCD screens by North American optometry at this time.

Cheers,
Scott

Scott D. Brisbin O.D., F.A.A.O.
Immediate Past President,
World Council of Optometry

#101 - 6203 - 28th Avenue
Edmonton, Alberta T6L 6K3
Canada

Tel.: (780) 440-2020
Fax: (780)) 466-2015
e-mail: sbrisbin@compusmart.ab.ca"

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