Citation

Blackwell HR. Highw. Res. Board bull. 1954; 89: 43-61.

Copyright

(Copyright © 1954, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The effect is analyzed of the following three optical filters upon visual detection under conditions encountered in driving: Two types of night-driving glasses, and a heat-absorbing windshield. A qualitative analysis is presented of the expected effects of optical filters upon visual performance in night driving. The analysis indicates that the three optical filters being used in night driving may be expected to reduce visual discomfort due to viewing bright headlights at night but htat losses in visual performance are to be expected. A method is described for quantitative prediction of the effects of optical filters upon visual detection at low luminance. Experiments are reported in which the effects of the three optical filters upon visual detection at low luminance was investigated. The results of the experiment seem to validate the predictive method for evaluating optical filters to a satisfactory degree. Test results are compared with predictions made by the method previously described. Implications are discussed of the experimental tests and the analyses for highway safety. it is concluded that losses in visual detection capability resulting in the use of optical filters at low