Disability glare evaluation and glaremeter

Abstract

This paper is concerned with disability glare. A test flash was exposed for 200msec, a background or glare source were presented steadily, and the threshold vursus radiance curves were determined. According to concept of equivalent veiling luminance, degrees of disability glare is shown by the threshold vursus radiance curves. Two formulas which Holladay and Westheimer & Campbel proposed were examined from our data, and we showed that formula of Holladay is more excellent than that of Westheimer & Campbel. However, constant values of Holladay's formula do not agree under different conditions. Therefore, we proposed glaremeter that degrees of disability glare is easily measured. If we use this apparatus, subjective values will be obtained based on concept of equivalent veiling luminance.