In this paper, some molding process parameters such as injection time, packing time, packing pressure and process temperature etc. were optimized by the Computer Aided Engineering (CAE) simulation (Moldex 3D) for injection molding of a plastic lens. Some experimental trials were carried out for verifying of the CAE simulation results with checking of the lens shrinkage and birefringence etc. as well. The results showed that, the recommended molding process parameters from CAE simulation and the actual experiments were almost the same, hence the CAE is a established tool based on the scientific approach to reduce experimental works, to identify critical parameters and to save substantial costs. Lately, a perfect plastic lens was gained by the Injection–Compression Molding process with the optimized process parameters by a CAE simulation.