Novel results relating to the characterization of microlens array production by simulation and micro injection molding were examined to produce precise micro-optics from Polymethylmethacrylate (PMMA), Polycarbonate (PC) as well as Polystyrene (PS). The microlens arrays show 100 lenses in a 10×10 array with a lens radius of 271 µm and a lens depth of 45 µm. The pitches between the lenses are fixed at 800 µm. The surface of the ultra-precision diamond end-ball milled microlens array mold was polished to reduce the surface roughness of the injection molded specimen. The injection molding parameters were optimized to get precise lens geometries with high shrinkage uniformity by simulation and experimental methods. The injection molding results show precise injection molded microlens arrays and PC microlens array shows the best geometrical results compared to the microstructured insert.