The evaluation for the interior visual environment has always been investigated in a steady state because of it's simplicity. But the workers in the room are actually never in such condition. The directions of their sight lines are varied from time to time, so their eyes are not always perfectly adapted to the luminances of their working planes. Considering this actual movement of their sight lines, authors have introduced the dynamic concept in the evaluation for visual environment, in which the change of adaptation luminance with time is taken into account. The purpose of this research is to develope the lighting design technique according with the worker's actual visual conditions. In this paper, the results on the observation about the fluctuation in the worker's visual field luminance, depending both on the movement of the worker's sight line and the variation of the daylight, are reported. In addition, the results of measurment of the time taking to change the visual direction are contained in this report. These data are thought to be useful to decide the design condition necessary to the dynamic evaluation technique for luminous environment.
