The effects of video display terminal (VDT) work on the visual system, the musculoskeletal system and general stress of the worker were investigated. The gross anatomy of the eye was reviewed including muscle systems and dynamic functioning. Vision problems were reported by the workers, specifically eye strain and burning or itching eyes, temporarily blurred vision, double vision, color fringes and permanent deterioration of visual acuity. Critical factors of the worker's environment were reviewed including degree of illumination (VDT image illumination, negative screen image, reflective screens, image quality and limited mobility), lighting effects (contrast, glare, reflections), and control methods (illumination, luminance contrast, light distribution, glare, screen reflection, evaluation of illumination). Characteristics of various VDT apparatus were considered including geometry of presentation (image generation, characters, dot and character spacing, chrominance and luminance, display polarity), glare reduction filters and contrast enhancement, hazard evaluation and control, and polarity. Postural stress was discussed including biomechanical, physiological and cumulative trauma. Specific areas of stress were reviewed such as the back, shoulder and neck, hand and arm, and leg. The biomechanics of the work station were considered with attention to the chair, keyboard table or support, VDT support, source document support, hand support, and foot rest. Other factors included were training, break in time, equipment selection, job stress, prompt problem detection, social environment, job security, performance monitoring, equipment maintenance, job scope, breaks, and pacing.
Division of Training and Manpower Development, NIOSH, U.S. Department of Health and Human Services, 56 pages, 20 references