[Psychophysiological fatigue in persons with normal and increased blood pressure during work with video display terminals].

In a field study, on the sample of 73 phototype-setters employed in newspaper press, various data of objective and subjective changes in psychophysiological functions were collected during work with Video Display Terminals. Using the "matched pairs" method, two groups were definitely formed; the first with normal blood pressure and the second with increased blood pressure. The subjects of 11 matched pairs within these two groups differed in value of blood pressure measured at the beginning of work, while they were matched with respect to sex, age, shift of work and the level of psychophysiological abilities that were examined at the beginning of work by fatigue tests. In addition to questionaries, the following methods were applied: flicker fusion frequency, dynamometry, reaction time measurement and measurements of retinal adaptation to darkness, convergence, stereoscopic vision and lateral phorias. The higher degree of general psychophysiological fatigue was discovered in group with increased blood pressure, but the same was not true for more specific visual fatigue that was more apparent in group of phototype-setters with normal blood pressure. According to one division of the degree of fatigue based on investigation of 50 different occupations with combined mental and physical work, it can be concluded that the degree of fatigue that was found in the group of phototype-setters with increased blood pressure during work with Video Display Terminals, is relatively the highest, so that it is very difficult for workers to adjust to it in biological sense.