Monitors are composed of pixels (tiny dots) in which the eye can not focus. The computer user has to "focus and refocus" to keep the images well defined. Another important factor is the 16.7 million colors generated by the video monitor, which overwhelm the muscles responsible for regulating the light input to the retina. Images in pixels require focus adjustment thousands of times a day. This results in tightening of the eye muscles. Additionally, after prolonged use of the computer, the blinking frequency, which causes dry, sore eyes, is decreased. As a result, the ability to focus decreases and headaches and neck pain may occur.
The main symptoms are: irritated eyes, dry and red, itchy or watery eyes; fatigue, sensitivity to light, sensation of weight of the eyelids and difficulty in reaching the focus; migraines, back pain and muscle spasms.
There is no evidence that computers cause vision problems. According to tests in American laboratories, monitors emit little or no harmful radiation under normal operating conditions. In fact, the amount of ultraviolet radiation produced by them is a small fraction of that produced by fluorescent lighting.
Some suggest that CVS symptoms occur as a result of external conditions related to the computer screen. These conditions may include poor lighting, poor lighting location, improper monitor position, dirty screen, and pre-existing eye problems.
To avoid the problem, some basic care must be taken.
Blink often:
The radiation emitted by the computer does not harm the eyes, but the habit of spending many hours uninterrupted in front of the monitor causes visual discomfort and blurred vision. The millions of colors generated by the monitor overwhelm the muscles responsible for regulating the entrance of light to the retina. When using the computer, the user moves the eyeball slightly and flashes, on average, five times less than normal. Blinking is important because it strengthens the muscles of the eyes and helps in maintaining its moisture.
Relax:
Ideally, take a 10 minute break every hour. The luminosity of the screen causes the pupils to close, causing a muscular effort, besides causing drowsiness and visual fatigue.
Eye drops:
Use lubricating eye drops if your eyes are very sensitive. However, follow medical advice because there are eye drops that contain vasoconstricting substances that clear the eyes but dry the mucous membranes.
The working table:
Try to place other work tools (telephone, calculator, pencil holder, etc.) as close as possible to the monitor. This providence lessens the need to "focus and refocus" and lessens the extent of movement to reach them. If you use documents next to your computer, try to keep them close to the screen (such as with clipped boards or brackets attached directly to the side of the monitor). This minimizes head and eye movements for maximum comfort.
Try to adjust the monitor:
- The top of the monitor should be at eye level or slightly below.
- The position of the monitor should be between 50 and 70 centimeters away from the eyes.
- The viewing angle for the monitor screen should be 10 to 20 °.
- Avoid glare. Beware of lights falling directly on your eyes (such as table lamps).
- The documents used should be close to the screen (on clipboards).
- Illuminate the environment where the computer is located.
- If necessary, use an anti-glare filter on the computer screen.
To avoid the syndrome described it is important to keep your prescription recipes always up to date. Therefore, consult the specialist doctor you trust, whenever necessary.