The art of optical illusions has a great impact on the visual dazzling of the client, as it has enriched the minds of designers with many tricks and methods that lead to visual enjoyment using different images and forms of optical illusions, which paved the way for them to create creative design visions from simple sources and to create modern visual aesthetics using technology and modern technology. This study aims to reach design standards and proposals that achieve the aesthetic and functional values ​​of the design through the harmony of the basic elements in the design, so that it is a complete, harmonious unit through the contribution of the art of optical illusions in the enrichment of interior design. Thus, the research problem can be identified in how to take advantage of the art of optical illusions in creating good harmony and diversity through the invisible link, which connects the parts of the design to each other and does not cause frequency and distraction and attracts the eyes in order to achieve aesthetic and functional values. The study is based on the idea that optical illusions, in all their types and effects, have a positive role, forming a complete, harmonious design unit that achieves harmony in the design. The study follows the descriptive, analytical and survey approach by identifying the elements of deception through interior design work and conducting an opinion poll to reach the main criteria for using optical illusions in interior design. The study found that achieving the aesthetic and functional values ​​of the design through optical illusion can achieve harmony between the sizes of different pieces of furniture within the space and merging them with backgrounds contributes to creating a harmonious eclectic style that will ultimately create a more interesting scheme. It also proved that to stimulate the feeling of depth of space, the focus is that the greater the degree of contrast in lighting between high-light areas and the logic of shadows, the greater the depth. Perhaps the most important finding of the study is that by using optical illusions, it is possible to correct some of the defects of the interior spaces without redesigning them by changing the visual perception of the interior space by visually enlarging it, or increasing its depth to achieve design visions characterized by visual dazzling.