The Glass Molding Process (GMP) produces large quantities of glass optical parts and provides the advantages of high molding accuracy, short production cycle, low cost, and little pollution. Developments in different sectors, such as cameras and telescopes, are prompting studies on the design of aspherical optical components. Modeling heat transfer and deformation at high temperatures are crucial aspects of studying glass because its properties are significantly influenced by temperature-induced phase changes. In this study, temperature changes and geometric deviations of lenses were studied with respect to heating, pressing, and cooling times and the heat capacity of the heater used. A 3D model was designed for the heating, pressing, and cooling steps, and heat transfer was subjected to numerical analysis considering the specific heat of glass and the temperature dependence of thermal conductivity. Lens molding temperature conditions were then analyzed with the heat capacity of the lens molding heating system. Lens molding conditions were derived by analyzing lens temperatures with respect to heating and cooling capacities at each process step.