Human beings have been using daylight for a long time. The daylight provides building occupants with psychological stability and also serves as lighting. However, the discomfort glare of windows produced from the daylight could be a severe problem as the working condition is getting more complicated and precise. Although numerous studies have been performed in order to solve this problem, most studies have been performed on Caucasians. The recent studies have revealed that there were differences between Caucasians and Asians in ocular activity, pigmentation, and color sensibility depending on the iris color. These data implies that it is difficult to directly apply the data from studies on the Caucasian to Asians whose physiological properties of eyes are different from those of the Caucasian. Therefore, it is necessary to develop an evaluation method of window discomfort glare, which may represent the visual feature of Asian appropriately. In the present study, we investigated the visual difference between Caucasian and Asians and established the nomo-graph to develop the method appropriate for the evaluation of the window discomfort glare for Asians. (c) 2006 Elsevier Ltd. All rights reserved.