The invention provides a contact lens manufacturing method comprising a process for removing unprocessed molded silicone hydrogel contact lenses from mold halves in a relatively efficient and consistent manner. A method of the invention comprises the combination of using a hydrophilic (meth)acrylamido monomer as one of major polymerizable components in a lens formulation for cast-molding of contact lenses, adding a post-curing treatment step which involves heating molds with molded lenses therewithin in an oven at a post-curing temperature higher than the curing temperature and under nitrogen gas flow at a higher flow rate, and using ultrasonic vibration energy for delensing. This method of the invention can be easily implemented in a production environment for enhancing the production yield.