The significance of mesopic visual performance and its use in developing a mesopic photometry system

In this research work detection rate was measured to evaluate the visual performance of human eyes at three mesopic light levels: 0.01, 0.1 and 1 cd m(-2). Effects on visual performance at mesopic levels were analysed and spectral sensitivity curves were indirectly drawn based on the visual performance values. A comparison between the research results of the brightness-matching method and the performance-based method proves that the results from the latter method are in essence compatible with the results from the bright-matching method, since they are both in accordance with the Purkinje shift. Furthermore, the results of the performance-based method reflect the contribution of the colour channel in the visual information processing system. (c) 2005 Elsevier Ltd. All rights reserved.