Light is very important in the interior design, whether we are talking about private residences, or we are talking about restaurants, offices or shopping centers. Over time, light becomes known being the fourth dimension of architecture. It influences not only the way we think and feel, but also the way we occupy a certain space. Depending of the light, certain rooms can borrow a dramatic note, while others can be immersed in a pleasant penny. Light can emphasize the depth of space, but projecting light on specific areas of a room will affect the way we move through that room. Several studies have been conducted in this field. It has been agreed that lighting affects the productivity at work. There are different rules, normative and design concepts for lighting installations. With modern solutions, a room can be illuminated entirely or partially. Low brightness makes the rooms look smaller, while the bright light gives the illusion of ample space. To create the impression of a generous interior space, the walls may be illuminated additionally without switching off in the room the general source of light.