Human factors and VDT design

Abstract

Visual strain is one of the most significant problems in working with VDTs. Field studies involving more than 1000 subjects have shown that both the optical properties of displays and the paper documents used are highly correlated with visual strain experienced by the operators. Somatic symptoms of discomfort, such as backaches, neckaches, or headaches, are significantly correlated to them and to visual strain. A VDT should be designed for a bright office. There are at least three relevant visual objects (keyboard, visual display unit, paper documents). The most relevant recommendations are to avoid specular reflections both on keys and on display and to provide an adjustable contrast, as much as 10:1. The use of filters cannot be recommendedfor all environments. Their use depends on the luminance distribution and the characteristics of ambient light in the environment.