Do the Luminance Levels of the Surroundings of Visual Display Units (VDU) and the Size of the Characters on the Screen Effect the Accommodation, the Muscle Load and Productivity During VDU Work?

This study aims at quantifying how much a background glare situation of a VDU, and different text sizes influence muscle load and production. Production was evaluated both as quantity of work, and number of errors that were made. The results showed no significant changes in the postural load in terms of electromyographic (EMG) measurements of m. trapezius and m. infraspinatus. However, a significant decrease in working speed and productivity was seen. There were no significant changes in the number of errors that was done. The transient myopic shifts (TMS) observed in an earlier study among presbyopic users [1] were not as clear in this study.

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