Spectral sensitivity for extrafoveal discomfort glare

Abstract

Previously published evidence suggests that the discomfort glare response to bright lights has greater short-wavelength spectral sensitivity than implied by the photopic luminous efficiency function, V(λ). The present paper summarizes a series of experiments to characterize spectral sensitivity for discomfort glare from nearly monochromatic light sources presented in the near extrafovea (5° and 10° off-axis). The results are consistent with increased participation in the discomfort glare response from short-wavelength cones and greater short-wavelength sensitivity as eccentricity increases. From the results an empirical family of luminous efficiency functions, V _DG(λ), for discomfort glare, is derived. Such data could have implications for specifications of roadway lighting, vehicle headlamps or other light sources that might contribute to discomfort glare.

Keywords:

• lighting
• glare
• discomfort glare
• spectral sensitivity
• luminous efficiency

Acknowledgements

The studies summarized here served as the basis for the Rensselaer Polytechnic Institute graduate theses of Peping Dee and Jennifer Watkinson. Others who contributed to these studies include Yukio Akashi, Andrew Bierman, Peter Boyce, Jie Chen, Russell Leslie, Martin Overington, Mark Rea and John Van Derlofske. Preparation of this manuscript was supported by the current and recent members of the Transportation Lighting Alliance: Automotive Lighting, DaimlerChrysler, General Electric, General Motors, Guide Corporation, Hella, OSRAM Sylvania, Philips Automotive Lighting, Visteon and Rensselaer's Lighting Research Center.