Citation

McFarland RA, Domey RG, Warren AB, Ward DC. Highw. Res. Board bull. 1960; 255: 47-56.

Copyright

(Copyright © 1960, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The relative effects are measured of light-absorbing, clear, and tinted windshield glass on the terminal levels of dark adaptation in a sample of 240 subjects who varied widely in age. The instrument used throughout was a modified hecht-schlaer adaptometer, which was housed in dark rooms.

CONCLUSIONS reached are: (1) both clear and tinted windshield glass reduce the amount of light that reaches the retina of the vehicle driver's eye, (2) tinted windshield glass transmits about 20% to 35% less light than clear windshield glass, (3) some areas of tinted windshield transmit less light than is permitted by the american standard safety code, (4) dark adaptation is a function of age, (5) clear windshield glass interposed between the testlight and the eye of the subject at terminal levels of dark adaptation is followed by a greater demand for light to just see the test stimulus, and therefore a rise in the dark adaptation curve, (6) tinted windshield glass interposed between the testlight and the eye of the subject at terminal levels of dark adaptation is followed by a demand caused by clear windshield glass, and (7) both clear and tinted windshield glass are impediments to vision under low levels of illumination for persons ranging in age from 16 through 89 years.