(3) Convergence and focusing problems. People who normally can't cross
their eyes are candidates for VDT fatigue. Problems in converging the eyes are often
accompanied by difficulty in focusing. The constant shifting in focal points from
keyboard to screen to paper adds to the problem. Consider the case of a woman
working at a computer 4 hours per day, who complained of eye aches and sleepiness.
She did not need glasses to correct farsightedness, nearsightedness, or astigmatism.
But a simple test, in which she was asked to focus on a pencil as it came nearer,
revealed that the image would split in two at 18 inches from her face. Eyeglasses that
corrected for this alleviated the VDT fatigue.
Figure 4-8. Your muscles will tire if you look at something close because it
causes your eyes to turn in toward your nose.
(4) Tension level. General fear or anxiety will cause the eyes to dilate, thus
rendering it difficult to focus. So, it is important to relax in order to reduce VDT fatigue.
(5) Failure to blink. Failure to blink is common because computer work
demands extra concentration. People get so engrossed in their work that they forget to
blink. If you forget to blink, your eyes will become dry and feel like they are burning.
Therefore, make a concerted effort to blink regularly.