A cast mold for manufacturing a contact lens or an intraocular lens, wherein the cast mold is provided with a central part and a bearing ring and a flexible connection between the central part and the bearing ring. Further, an injection mold is provided for manufacturing such a cast mold and a method for manufacturing such a cast mold. The injection mold is provided with a mold cavity with a plunger biased by a spring towards the mold cavity which serves for compensating shrinkage which occurs during the curing of the plastic injected into the injection mold. Also described is a method for manufacturing a contact lens or intraocular lens with the aid of the cast mold, as well as a contact lens or intraocular lens obtained with this method.