Intraocular pressure control system (IOP) (200) for implantation in an eye of a patient to provide drainage from an anterior chamber of the eye to a drainage location in the eye, comprising: a valve system (230) that it has a completely open flow position and a closed zero flow position, allowing the open flow position the fluid flow through the valve system, substantially preventing the closed zero flow position the fluid flow through the valve system ; a sensor system (210) comprising a first sensor arranged to detect a first representative pressure of a real-time parameter of the eye; and a controller (212) arranged to receive data from the sensor system (806) and compare (808, 812) the data representing the pressure detected with a preset upper pressure threshold and a preset lower pressure threshold to determine whether to change the state of the bimodal valve system from one of a completely open flow position and the zero closed flow position to another between the fully open flow position and the closed zero flow position, characterized in that the valve system (230) comprises: a housing (502); a protuberance (508) centrally located in the flow control chamber (530) and adjacent to the second side of the flexible membrane (538), the protuberance (508) having an inlet opening (504) centrally located in the protuberance (508) ); a flexible membrane (538) coupled with the housing, the flexible membrane having a first side and a second side; a flow control chamber (530) delimited by an interior of the housing and a first side of the flexible membrane, the chamber containing a drive fluid (532); an outlet orifice (506) located in the housing adjacent to the second side of the flexible membrane; a passage located inside the housing (502), the passage fluidly coupling the inlet opening (504) to the outlet opening (506); wherein when the valve system is in the closed zero flow position, the flexible membrane is adapted to expand towards the protuberance (508) to prev