The success of the interior design depends on the ability of the designer to create and shape, taking into account the principles and laws of lighting and color, choosing materials and calculating the reflection and absorption coefficients of colors and materials and its relationship to natural lighting of the place where the work of the interior designer in distributing and calculating lighting for engineering projects is determined by drawing an initial framework for the proposed interior design elements - and to the designer To make multiple changes with regard to lighting sources, design materials, and suggested colors so that in the end he makes sure that there is no variation in the lighting of the surfaces involved in the design, which leads to physical and psychological troubles for users of the place.The research was interested in studying, discussing and analyzing functional and aesthetic considerations and methods of mathematical calculations in controlling and determining the proper lighting in interior design projects with the aim of reaching the mechanism governing the resulting optical design process in a way that ensures the achievement of identity and its elaboration in a general framework that helps the interior designer to innovate and develop.