Almost all of us will agree that staring at a monitor harms the eyes. Those who spend the night surfing the Internet often complain of burning eyes, flickering lids and blurred vision.
Studies show that the eyes shift about 30,000 times in an eight-hour work session at the PC. The overtaxed eye cannot possibly keep up with this kind of performance. Hazy and flickering monitors further add to the danger. It has also been established that looking steadily at the screen for a long time reduces the blinking frequency. This leads to the ‘Dry Eye Syndrome’. In extreme cases, the cornea can dry up, affecting vision. In some cases, this can also result in the loss of sight.
When you work intensively on a computer, you may develop headaches, backache, sore or burning eyes. In the first few months of intensively using a PC you may just ignore all these problems. These are your body's natural ways of telling you that all is not right in your eye’s relation with the PC. If left unattended, all these factors may end up giving you CVS (Computer Vision Syndrome).
CVS is caused by visual fatigue occurring due to constant shifting and focusing of the eyes between the screen, document and keyboard, which is roughly about 25,000 times a day. The eyes have to accommodate, converge and adapt under dissimilar ambient light on the keyboard, monitor and the document.
It is necessary to understand that reading text from a computer screen is significantly different from reading print-based materials. Unlike print-based materials which reflect light, the computer monitor (the visual display unit, VDU) is a self-illuminated object. Looking directly at the computer screen is somewhat like looking into a light source. Less surrounding light may be needed or the VDU may cause discomfort to the eyes. Poorly designed work environments may thus accentuate the development of CVS.
METHODS FOR PROTECTING OUR EYES:
Now let us take a look at some methods for protecting our eyes. Following these measures will ensure that we are saved from problems like CVS.
1. Go in for non-interlaced monitors. In many parts of the world, such monitors are a norm. Not so in
2. Adjust the furniture and monitor position for a comfortable viewing distance and angle plus easy access to the keyboard and other devices (e.g., a mouse). Most users prefer a viewing distance of 50-66 centimeters (20-26 inches) from the eye to the screen, or more, if large characters are displayed. Greater distance is recommended, as this lessens the probability of visual discomfort since it requires less convergence of the eyes and therefore, less eyestrain. Appropriate screen location depends on eye position and line of sight. Since the most comfortable line of sight is at least 10 degrees below horizontal, the normal line of vision should be from the eye to the top of the screen.
3. Black font on a light background is easy on the eyes. Light is broken up by the eye lens and is perceived as varying wavelengths. The eye has to work harder to register colours than when seeing a black and white picture. It is better that you do not work with fonts less than 7-point size.
4. Adjust the brightness control or contrast knob (on some displays) to a comfortable setting and use a task light, if needed, for working with printed material.
5. Glare from the screen can usually be modified by lowering ambient light, drawing window covers against bright light, wearing less reflective garments, choosing more appropriate task lighting, and cleaning the display screen. Use fluorescent tube lights or bio-lamps: these come closest to the spectral composition of natural daylight.
6. Keep the display screen clean, especially during conditions of low humidity (e.g., in the winter). This is important as this reduces screen dust. Additionally, neutral-density or micromesh filters may be helpful in enhancing contrast or reducing glare.
7. And finally, rest your eyes every few minutes. Look away from your monitor at regular intervals.
