The purpose of this thesis is to develop an intelligent aircraft window system for visual comfort control based on electrochromic windows that can change the transparency depending on passenger’s needs and visual comfort. In the current window system, window transparency is controlled manually. The system developed in this thesis is an automatic system. Under this development, a mock-up is set up to mimic a section of cabin with an electrochromic window along with a simulated sunlight source and several light sensors. To measure visual comfort, the daylight glare index (DGI) is adopted. Based on DGI, a fuzzy logic classifier is developed to evaluate visual comfort/discomfort. This is followed by developing a fuzzy logic controller that can automatically adjust the window transparency based on the measured DGI level and the rate of change of DGI. DGI set point for different individuals, the effect of illuminance and color temperature are also discussed.