We have been discussing some of the many factors that lead to Computer Stress Syndrome. We'll focus now on protecting our eyes. Try as we like, there may be situations where the location of the monitor and the lighting of the room are not ideal or may even be deleterious. Since glare on the monitor causes serious stress to the eyes, we will do everything that we can to reduce the light on the screen from nearby windows, overhead fluorescent lights and simple improper placement of the monitor.
While the wearing of a simple billed cap often helps against the overhead lighting problem, there are two devices that may help us in eliminating the glare. The first is an antiglare visor that adheres to the top and two sides of the monitor. It is a piece of fiberboard that is lined with an antiglare surface and is cut in such a way that when it is placed upon the monitor, the monitor is well shielded from extraneous light and glare. These are inexpensive and available from most computer suppliers. The use of this visor will improve the definition of the image as well as increase the contrast so that one will see a sharper image easier and without strain.
The other device is a filter that fits in front of the monitor window. There are several kinds of these filters and not all filter the same ranges of energy. There are those that will filter brilliance, color, glare, ionization and radiation. Some only do part of these. The use of this kind of filter will also increase the quality of the image tremendously. The greatest benefit, however, is to decrease the irradiation from the screen, which we usually depend upon distance to protect us from.
The emanations of extremely low frequency (ELF) and very low frequency (VLF) rays are present in every video (TV) tube or monitor. Very few monitors come with a built in filter to lower the dosage from these rays. The ELF and VLF rays are similar to those that are emitted from electric shavers, electric blankets, heating pads, hair dryers, toasters, and other common objects that are around the home. Some studies have shown that women who work before VDT's (visual data terminals or monitors) from 8-10 hours per day for extended intervals tend to have irregular menstrual periods and that pregnant women may miscarry or their off-spring may develop birth defects. There are also some studies that suggest that those who work long hours before these terminals are more likely to develop cataracts. This evidence seemed to be sufficient for Sweden to set up rather strict emission standards for their manufacturers. Other countries have less strict standards, or none at all.
I must say that there is no definitive study that actually proves a causal relationship between ELF and VLF emanations and any problems suffered by humans. Since we cannot say unequivocally that these rays, like radio and television waves, are harmless, it behooves us to take all of the precautions that are available. That is, we should use the best filters that we can find at all times, stay at least three feet from the back or sides of a monitor, sit at least an arm's length from the screen of the monitor, and turn off the monitor when it is not in use. Even with a screen saver working, the monitor still emanates these ELF and VLF radiations.
Continued with part IV next month.