Stereomicroscopes allow us to observe specimen structure three-dimensionally and perceive their depth. In general, three-dimensional images are derived from the brain’s interpretation of the two slightly different images received from each of the retinas. Stereomicroscopes utilize the functions of both eyes and brain to perceive depth by transmitting two images tilted at a small angle to generate stereoscopic vision. These microscopes are necessary for specimen micromanipulation or examination required in a large and comfortable working space. Some other features such as the wide field of view and variable magnification are also helpful for industrial micro-assembly, or for biological research that needs careful manipulation and vulnerable living organisms. However, a demand for wider variable magnification range has been increasing along with the various applications. We reported the “Perfect Zoom System” which can make some of the zoom lens groups move perpendicular to the optical axes in the low-power state as a solution to this problem in 2015. This technique improves the zoom ratio and enables more applications with additional parts. Here, we review developments in stereomicroscopes with the “Perfect Zoom System” and discuss its practical applications.