ABSTRACTManually operated solar shades have a significant impact on indoor visual comfort. This research investigates occupants' appropriate seating position and view direction in a west-facing office cell using a previously developed shade behavior model. The non-dominant sorting genetic algorithm (NSGA-II) based Multi-objective optimization was adopted to identify the optimal and near optimal solutions. Daylight and glare index were used as two visual comfort objectives for optimization and robustness of optimization results against shade behavior uncertainty that was analyzed using statistical analysis. Results show that near optimal solutions can be used instead of the optimal one since they provide more flexibility in seating positions while maintaining almost the same visual comfort performance. And thus, the appropriate seating position considering occupants' preference is 1.5m away from the external window with two view directions near parallel to the window for west-facing office rooms.