Already in the early years of computerization was noted specific visual fatigue among users of displays, a common name of "computer vision syndrome" (CVS-Computer Vision Syndrome). Its causes few. And above all - formed over millions of years of evolution of human visual system that is suited to the perception of objects in the reflected light (Nature paintings, drawings, printed texts, etc.) rather than to work with the display. The image on the display is fundamentally different from the usual eye observation of objects - it glows, is composed of discrete points, but mertsaet, ie, those points with some frequency zazhigayutsya and extinguished; color computer image does not match the natural color (light spectra luminophores differ from the absorption spectra visual pigments in the cones retina that are responsible for our color vision). But not only features the image on the screen cause visual fatigue. When working on the computer for hours at the eye is never necessary phases of relaxation, eye strain, their performance declines. Much of the load body is when you enter the information as the user is often forced to move from screen to view text and a keyboard at different distances and in different lighting.
What is expressed visual fatigue? Today, millions of users complain zatumanivanie vision, difficulty in moving sight to the neighbors long and distant to near objects, the apparent change in the color of their dvoenie, unpleasant sensation in the eye - the sense of burning, "sand", redness century, when the pain Traffic eye.