Abstract: The disclosure includes devices and methods for controlling fluid flow. The devices include a tube configured to receive fluid from a fluid source; and a valve for controlling fluid flow through the tube, the valve responsive to fluid pressure in the tube. The valve includes a first magnet outside the tube at a fixed first distance from the tube and a second magnet outside the tube substantially opposite the first magnet and at a second distance from the tube, the second distance greater than the first distance. The valve includes a ferromagnetic fluid within the tube between the first magnet and the second magnet and held in position by a magnetic field generated by the first magnet. The amount of ferromagnetic fluid is sufficient to seal the tube when the fluid pressure is below a threshold pressure set by the second distance between the second magnet and the tube.

Abstract: The disclosure includes devices and methods for controlling fluid flow. The devices include a tube configured to receive fluid from a fluid source; and a valve for controlling fluid flow through the tube, the valve responsive to fluid pressure in the tube. The valve includes a first magnet outside the tube at a fixed first distance from the tube and a second magnet outside the tube substantially opposite the first magnet and at a second distance from the tube, the second distance greater than the first distance. The valve includes a ferromagnetic fluid within the tube between the first magnet and the second magnet and held in position by a magnetic field generated by the first magnet. The amount of ferromagnetic fluid is sufficient to seal the tube when the fluid pressure is below a threshold pressure set by the second distance between the second magnet and the tube.

Abstract: A dry-eye treatment method includes collecting fluid from the inside of the eye and transporting the collected fluid into the eyelid fornix, where it accumulates. At each blink, accumulated fluid from the fornix is spread across the surface of the eye.

Abstract: A shunt for relief of intra-ocular pressure includes a pressure-relief valve and a jacket enclosing the pressure relief valve. When implanted on the sclera of an eye, the jacket protects the valve from interference by a capsule formed on the shunt.