The cataract is a disease of that crystalline lenses get opacified because of aging or other causes. In case of serious cataract, opacified lenses must be replaced with artificial lenses. The PEA (PhacoEmulsification Aspiration) is, in recent years, a major technique for removing opacified lenses. There is, however, a problem called as surge phenomenon still to be solved in the PEA. The surge phenomenon is that an intracameral pressure accidentally falls down to an extreme and this would invite a possibility of blindness in the worst case. Though there exist some passive countermeasures against it, but not enough to secure the safety of surgical operation. This paper describes how to control an intracameral pressure by down-seized gear pump and a modern control theory. We could simulate a surge phenomenon in our modeled eye. Having designed a SAC (Simple Adaptive Control) servo system, we succeeded to minimize the surge pressure to an allowable level.