Some factors influencing vision through meshes
The problem of designing window screening devices involves the optimization of several conflicting environmental requirements for which few data exist on the aspect of outward vision. Three experiments are described in which the vision obstructing characteristics of a mesh-screening material are investigated. Experiment 1 shows the relevance, in a field situation, of employing a factorial design. Experiment 2 used a one-eighth replicate 2 11 factorial design to determine the more significant variables and first order interactions responsible for limiting vision through a mesh. The measurement of visual acuity and the technique of ratio scaling were used to record visibility. Visual task luminance was selected for further study in experiment 3 where Stevens’ power law was established between direct magnitude estimates of ‘ease of seeing’ and visual acuity scores. It is suggested that this technique be extended to scale the effects on visibility of a number of the other variables thus making possible the total functional and cost optimization of window screening materials.