Assessment of discomfort glare in motor vehicle lighting

Discomfort glare in motor vehicle lighting has been investigated experimentally using a scale model with stationary test and glare fields. Influences of the size of glare source and age of observer were not investigated Results indicate that the effects of glare illuminance, adaptation luminance, angle of glare and number of glare sources on discomfort glare assessment can be described mathematically. Each parameter was examined individually and the assessments are compared with those obtained previously for disability glare. A general formula is derived which allows the discomfort glare to be calculated for arbitrarily selected combinations of the parameters. The results relate to motor vehicle lighting but are also applicable to street lighting.