The Effects of Infrared- Reflective and Antireflective Glazing on Thermal Comfort and Visual Performance: a Literature Review

A green windshield at night reduces acuity from 20/32 to 20/46, and combined with pink glasses to 20/60. Resolution thresholds decreased from 10 to 42 seconds of arc, so that a pair of objects that could be seen through a clear windshield at 100 feet decreased to 25 feet through the green. Other visual functions found "defective in night-driving conditions with tinted glass" were stereo acuity, instant counting span, discrimination of angular velocity, simultaneous contrast, intensity change, and direction of a line target." Headlights should be designed larger in area "since glare is inversely proportional to the area of the source." Title: Effect of aftermarket automobile window tinting films on driver vision (LaMotte et al., 2000). Abstract: This study was conducted to determine the level of automobile window tint that causes a significant reduction of vision for automobile drivers. Contrast sensitivity was measured on 20 participants, of whom 10 were age 20 to 29 years and 10 were age 60 to 69 years, through a stock automobile window (control) and two windows darkened with plastic film. For the younger drivers, a car window with 37% transmittance did not significantly reduce contrast sensitivity, but a darker tint of 18% transmittance reduced contrast sensitivity at higher spatial frequencies. For the older drivers, a tint of 37% transmittance significantly reduced midtohigh spatial frequency contrast sensitivity. The typical state standard (no tint with less than 35% transmittance) would thus seem to be appropriate for younger drivers; however, further examination of the standard may be necessary in regard to older drivers. Actual or potential applications of this research include guidelines and regulations regarding tinting of automobile windows. This study was conducted to determine the level of automobile window tint that causes a significant reduction of vision for automobile drivers. Contrast sensitivity was measured on 20 participants, of whom 10 were age 20 to 29 years and 10 were age 60 to 69 years, through a stock automobile window (control) and two windows darkened with plastic film. For the younger drivers, a car window with 37% transmittance did not significantly reduce contrast sensitivity, but a darker tint of 18% transmittance reduced contrast sensitivity at higher spatial frequencies. For the older drivers, a tint of 37% transmittance significantly reduced midtohigh spatial frequency contrast sensitivity. The typical state standard (no tint with less than 35% transmittance) would thus seem to be appropriate for younger drivers; however, further examination of the standard may be necessary in regard to older drivers. Actual or potential applications of this research include guidelines and regulations regarding tinting of automobile windows.