COMPUTER VISION SYNDROME

The use of computers in the work environment and housing is one of the revolution in the field of
technology. Instruments have become part of our lives, and to improve productivity and work efficiency. In the year 2000 is considered that 75 percent of men working involves computer.
One of the negative impact of the extensive use of computers for the health of interference is referred to as computer vision syndrome (CVS).
According to The American Optometric Association, CVS is a collection of symptoms okuler (eye) and non-okuler that arise after the work in front of a computer screen or video display terminal (VDT).
CVS found on 75 percent of workers who use computers for 6-9 hours each day. In United States and England, CVS reported occurred in 12.4 percent and 9 percent of all patients came to the eye doctor. CVS symptoms include tired eyes (asthenopia or eyestrain), eye feels dry, sandy, or heavy feeling, blurred vision, which can be accompanied by headache (especially the forehead and the right or left of the head), neck muscle pain, and back.

Mechanism how to occur and factor into effect
Mechanism of a CVS is not fully known, but suspected a combination of factor of the surface, accommodation, other factors outside the eye, characteristics of the computer, and regulation of the room.
Surface of the eye which is always wet because the coated layer of tears (tear film) may be in the CVS interference experienced by the environment, such as the use of air conditioner (AC), the fan, and decrease in reflex blink at work. In normal circumstances, eyelid blink 16-20 times per minutes. Research shows that the frequency flicker is reduced to only 6-8 times only every minute on the people who work with the computer screen. This result in eye quickly become dry. In addition, the surface of the eye may be susceptible to interference due to the decrease production of water with increasing age, the hormone changes in women, the disease or consumption of certain medications (such as antihistamine or anti-hypertension drugs), and the use of contact lenses.
Accommodation or changes the structure of the eyes can see the focus for a short distance. Letter on the computer screen is very different to the text in the paper as arranged on the pixels, or dots that composed form letters or numbers. To see the letters / numbers on a computer screen, eye-hold accommodation so that the cause fatigue or eyestrain. Fortunately, usually changes in accommodation are reversible at the end of the day or on holidays. Some experts assume that the accommodation due to the use of computers can stimulate for miopi (process of a dim far), but has not been proven with research.
Painful muscle stiffness or neck, shoulder, back and head movements occurred as a result, neck, shoulder and to the front, which tended to be computer users to see more clearly. Muscle pain complaints also occur on the user bifocus or progressive glasses (in the workers who already require glasses to read the plus), where they tend to move the head back when read the text on the paper, and promote the vision when the focus back to the screen computer.
Quality display (impression on the computer screen), where the contrast is less, will make it look
letters or numbers on a computer screen. In addition, the higher resolution screen, image border
will firmly so that the eye can see without excessive accommodation.
Impact and Corrective Action

CVS is not yet proven can cause vision and health of heavy, but of course can reduce worker productivity and efficiency. CVS needs to be regulated, with management of the interference, the work environment, and improving conditions ergonomic worker.

To overcome dry eyes, eye lubricate can be done with various drugs tear drops artificial (artificial tears). Workers who have a deviation refraction (need glasses) need to corrected model with the power and the right glasses. Take a rest periodically during using a computer, especially after four hours work constantly to relaxing
eye accommodation. A way that is suggested as an alternative is to apply a formula "20-20-20", namely: every 20 minutes of looking at things that 20 feet (approximately 6 meters) for 20 seconds.

The light source can be placed indoors away from the computer screen, give the curtains on the window or provide filters on a computer screen.

Position the computer monitor is placed so that workers achieve a good ergonomic position. Recommended distance to the screen of 34-40 cm, with the location of the center of the screen 10-20 degrees (or 5-6 inches) below the line of sight. Body postures should be good to avoid muscle pain neck, back, shoulders, and head.

Avoid using dark backgrounds. Black letters on a white background is best to avoid Computer Vision Syndrome affected.
Ventilation room is set so that workers get enough fresh air but avoid the flow of air that leads directly to the face, as this encourages the occurrence of drying faster.