The present invention relates to a method (120) for providing light to a room, the room comprising a wall, the method (120) comprising arranging (122) in the room a light source having a light intensity control device, providing (124) a model for light intensity simulating light conditions in a first period of a day, and operating (126) the light intensity control device in accordance with the model so that light is provided to the room. Further the present invention relates to a system for providing illumination in a room, the room comprising a wall, the system comprising a light source including one or more individual light sources, the light source including a light controlling device for controlling intensity and/or direction of light and/or color of light emitted, a controller device configured to control the light controlling device in accordance with a simulation program simulating changes in daylight over a period of time.