A drainage device for implantation in an eye of a patient to treat an ocular condition is disclosed. The drainage device includes a housing, a multi-compartment flow control chamber, and a membrane. The housing includes an entrance port and an exit port connected by a fluid flow passageway. The membrane is disposed between the fluid flow passageway and the multi-compartment flow control chamber, which includes a first compartment and a second compartment in fluid communication with each other. The first and second compartments are structurally arranged to limit contact of gas with the membrane, which is disposed between the fluid flow passageway and first compartment. The membrane is configured to affect flow through the fluid flow passageway by deflecting in response to pressure in the flow control chamber.
