Lighting and quantitative parameters of visual tasks

The paper discloses the results of a series of tests carried out to evaluate the complexity of visual tasks for the purpose of specifying the fundamental principles for the standardization of lighting conditions. In addition to the parameters of the difficulty of visual tasks which are in current use in the practice of standardization, i.e., target dimensions, target contrast with the background, a certain number of additional characteristics are proposed and examined. The results of tests to evaluate the influence of these characteristics on the complexity of the visual task are reported. The relationship between the difficulties of visual tasks performed at different working levels of the visual analyzer is considered. It is shown that the degree of influence of external parameters on the complexity of a visual task depends to a great extent on the working conditions. The experimental data obtained result in certain conclusions and propositions regarding further investigations of the influence of qualitative and quantitative lighting characteristics on the visual capacity.