Precision glass molding (PGM) technology is a cost-efficient process for the production of micro/nanostructured glass components with complex surface geometries. The stress distribution, surface profile, and reduced refractive index of the molded lens are based on the lens being fully formed. The process of the deformation of the glass preform is rarely discussed, especially in the case of multi-machining parameters in the experiment. The finite element method (FEM) was adopted to analyze the glass preform deformation. Due to the phenomenon of incomplete deformation of the glass preforms in the experiments, two groups of finite element simulations with different boundary conditions were carried out with MSC.Marc software, to reveal the relationship between the deformation progress and the parameters settings. Based on the simulation results, a glass preform deformation model was established. The error between the model result and the simulation result was less than 0.16. The establishment method of the glass preform deformation model and the established model can be used as a reference in efficiently optimizing PGM processing parameters when the designed lens has two different base radii of curvature.

As the prevalence of myopia among adolescents continues to increase, the design and fabrication of myopia control lenses have become an important research direction in modern optics. Existing myopia control lenses mostly adopt purely refractive structures, which suffer from limited design freedom, insufficient chromatic aberration suppression, and relatively large lens thickness, thereby restricting further improvement of optical performance. This paper proposes a refractive–diffractive hybrid design and fabrication method for myopia control lenses. Centered on a harmonic diffractive optical element (HDOE), an optimization model is established to balance achromatization performance and fabrication feasibility. To address the challenges of small period width, tool shadow effect, and sensitivity to machining tolerances in diffractive lenses with large-aperture and high-additional-power, harmonic design is employed to increase the period width, thereby reducing fabrication difficulty and mitigating the influence of shadowing errors on diffraction efficiency. On this basis, two lenses with different phase structures are designed: one adopts a conventional diffractive correction phase to verify the role of HDOE in achromatization and edge-thickness reduction, while the other adopts a high-degree-of-freedom smooth phase to achieve a continuous multifocal visual effect. Both lenses are fabricated by single-point diamond turning (SPDT), and the effects of surface profile and machining parameters on performance are analyzed. Simulations and measurements show that the proposed method provides stable diffraction efficiency and effective chromatic aberration correction across the design band, while reducing the edge thickness by approximately 37.85% without additional thinning of the aspheric substrate. The results indicate that the refractive–diffractive hybrid design provides a feasible design and fabrication approach for functionally more complex myopia control lenses.