Over the past two decades, precision glass molding has gradually become a competitivehot-replicating manufacturing technology for precision glass optical components. Butform errors occur on surface of molded glass optics as a result of a diverse range of effectsincluding viscoelastic relaxation and thermal shrinkage of optical glass material during themolding and cooling processes. Conventionally these errors can be compensated solelyvia time-consuming and cost-intensive try-out molding experiments.