A Measurement Method for Visual Fatigue Through Clarification of Its Effects on the Human Body and Related Factors in VDT Operations.

本研究在考察视觉疲劳之前，阐明了人类视觉信息加工的一种机制，即基于VDT操作的加工。人类视觉信息加工分为三个子过程。对视觉信息从内部表征阶段到识别阶段的识别过程进行了建模，针对VDT操作对人体的影响，重点研究了VDT操作对人类视觉系统和中枢神经系统的影响。两个实验被用来检验这些效应，并将VDT操作与硬拷贝任务进行了比较。结果表明，VDT作业比硬拷贝作业对视觉系统和中枢神经系统的影响要大得多。以视觉疲劳和工作绩效为特征，考察了工作节奏的影响。研究结果表明，认知任务采用自进度作业的效果明显好于机器进度作业。为了阐明作业内容的影响、表征作业内容的两个因素与视觉疲劳的关系，本研究提出了视觉疲劳的测量方法。方法是测量中枢神经系统通道容量的下降。该方法被应用于不同的任务和工作环境。结果发现，该方法能够检测不同工作环境中的疲劳程度。

This research clarified a mechanism of human visual information processing as based on the processing of VDT operation, before examining visual fatigue. Human visual information processing was divided into three subprocesses. The recognition process from an internal representation stage of visual information to a recognition stage was modeled.Concerning the effects of VDT operation on human body, the effects on human visual system and central nervous system were focused on. Two experiments were carried out to examine these effects, compared VDT operation with hardcopy task. As the result, there were much more effects of VDT operation than those of hardcopy task, not only to the visual system, but also to central nervous system. The effects of work pace were also examined with visual fatigue and work performance as characteristics. It was obtained as the result that the self-paced work is much better for cognitive tasks than the machine-paced work.In order to clarify the effect of work contents, the relationship between two factors characterized work contants and visual fatigue.With considered the above results, a measurement method for visual fatigue was proposed in the present research. The method is to measure the decrease of channel capacity of central nervous system. The proposed method were applied to various tasks and work environments. As the results, the method was found to be able to detect the degrees of fatigue among various work environments.