An intraocular pressure control system for implantation in an eye of a patient to provide drainage from an anterior chamber of the eye to a drainage location at the eye, comprising: a valve system having a fully open flow position and a closed zero flow position, the open flow position permitting fluid flow through the valve system, the closed zero flow position substantially preventing fluid flow through the valve system; a sensor system comprising a first sensor arranged to detect a first pressure representative of a real-time parameter of the eye; and a controller arranged to receive data from the sensor system and compare (808,812) data representing the detected pressure to a pre-established upper pressure threshold and a pre-established lower pressure threshold to determine whether to change the state of the valve system in a bimodal fashion from one of a fully open flow position and the closed zero flow position to the other of the fully open flow position and the closed zero flow position, characterized in that the valve system comprises: a housing; a boss centrally located in the flow control chamber and adjacent to the second side of the flexible membrane, the boss having an entrance port centrally located in the boss; a flexible membrane coupled with the housing, the flexible membrane having a first side and a second side; a flow control chamber bounded by an interior of the housing and a first side of the flexible membrane, the chamber holding an actuator fluid; an exit port located in the housing adjacent to the second side of the flexible membrane; a passage located inside the housing, the passage fluidly coupling the entrance port to the exit port; wherein when the valve system is in the closed zero flow position, the flexible membrane is adapted to expand towards the boss to prevent fluid flow from the entrance port. a valve system having a fully open flow position and a closed zero flow position, the open flow position permitting fluid flow through the valve system, the closed zero flow position substantially preventing fluid flow through the valve system; a sensor system comprising a first sensor arranged to detect a first pressure representative of a real-time parameter of the eye; and a controller arranged to receive data from the sensor system and compare (808,812) data representing the detected pressure to a pre-established upper pressure threshold and a pre-established lower pressure threshold to determine whether to change the state of the valve system in a bimodal fashion from one of a fully open flow position and the closed zero flow position to the other of the fully open flow position and the closed zero flow position, characterized in that the valve system comprises: a housing; a boss centrally located in the flow control chamber and adjacent to the second side of the flexible membrane, the boss having an entrance port centrally located in the boss; a flexible membrane coupled with the housing, the flexible membrane having a first side and a second side; a flow control chamber bounded by an interior of the housing and a first side of the flexible membrane, the chamber holding an actuator fluid; an exit port located in the housing adjacent to the second side of the flexible membrane; a passage located inside the housing, the passage fluidly coupling the entrance port to the exit port; wherein when the valve system is in the closed zero flow position, the flexible membrane is adapted to expand towards the boss to prevent fluid flow from the entrance port. a housing; a boss centrally located in the flow control chamber and adjacent to the second side of the flexible membrane, the boss having an entrance port centrally located in the boss; a flexible membrane coupled with the housing, the flexible membrane having a first side and a second side; a flow control chamber bounded by an interior of the housing and a first side of the flexible membrane, the chamber holding an actuator fluid; an exit port located in the housing adjacent to the second side of the flexible membrane; a passage located inside the housing, the passage fluidly coupling the entrance port to the exit port; wherein when the valve system is in the closed zero flow position, the flexible membrane is adapted to expand towards the boss to prevent fluid flow from the entrance port.