Change the distance of your focusing during rest periods. Look out the window at a far object if possible, or focus on something across the room. The location of the visual target plays a major role in determining sitting posture. Visual requirements result in the user positioning the body so that the face is parallel to the viewing surface. This principle should be remembered when determining placement of a monitor.
Visual acuity determines the optimal viewing distance to the monitor.
Although ANSI and Canadian standards require a minimum' viewing distance of 12 inches, research studies have shown a preferred viewing distance of 30 to 40 inches from the screen. Standards also require that the user's viewing area should be located between 0 and 60 degrees below the horizontal plane. Recent studies have demonstrated that it is easier to look downward rather than horizontally or upward. Lower targets may be more comfortable for users, especially when preferred viewing distances are considered. These findings suggest that VDT monitors should possibly be located lower and further away from the user than previously thought to offer greatest visual comfort.