Taptagaporn S, Saito S
Department of Public Health and Environmental Science, Tokyo Medical and Dental University, Japan.
Ind Health. 1993;31(1):13-28. doi: 10.2486/indhealth.31.13.
To recommend a comfortable visual display terminal (VDT) workstation design in an aspect of visual ergonomics, physiological resting states of the eye in 3 visual systems, pupil, vergence, and accommodation, were objectively investigated in 3 experiments. Experiment 1 ascertained a positive display polarity (dark characters on a bright background) and an illumination level of 500 lx to be the most appropriate working conditions, by using pupil analysis and subjective visual comfort in 10 subjects. Dark vergence, in experiment 2, was evaluated to be at a distance of about 50 cm from the eye, as an average in 14 subjects. Dark vergence was found to shift farther with an upward gaze while a nearer shift occurred with a downward gaze. In experiment 3, the average dark focus for 11 subjects was found to be 1.4 diopters (D) or a distance of about 74 cm from the eye. The positive correlation between refractive status of the eye and dark focus was statistically significant (r = 0.602). The ergonomic recommendations for a VDT workstation obtained in this study are a positive display polarity with an appropriate lighting condition, a downward gaze, and a viewing distance between 50 and 70 cm. These recommendations are considered to reduce visual fatigue due to prolonged VDT work and to facilitate visual comfort at work.
为了从视觉人体工程学的角度推荐一种舒适的视觉显示终端（VDT）工作站设计，我们在三个实验中客观地研究了眼睛在三种视觉系统（瞳孔、聚散和调节）中的生理休息状态。实验1通过对10名受试者进行瞳孔分析和主观视觉舒适度评估，确定正显示极性（亮背景上的暗字符）和500勒克斯的光照水平是最合适的工作条件。在实验2中，对14名受试者的平均评估结果显示，暗聚散距离眼睛约50厘米。研究发现，向上注视时暗聚散距离会更远，而向下注视时距离会更近。在实验3中，11名受试者的平均暗焦点为1.4屈光度（D），即距离眼睛约74厘米。眼睛屈光状态与暗焦点之间的正相关具有统计学意义（r = 0.602）。本研究得出的VDT工作站人体工程学建议是：采用正显示极性并搭配适当的光照条件、向下注视以及50至70厘米的观看距离。这些建议被认为可以减少因长时间使用VDT工作导致的视觉疲劳，并提高工作时的视觉舒适度。
