Drainage devices are provided for draining aqueous humor present in the anterior chamber of an eyeball. Such devices include a drainage tube extending axially along a tube axis between a distal end and a proximal end. The distal and proximal ends are at least partially open and are beveled in the same direction. A support flange extends from the proximal end of the drainage tube and includes a plate-shaped portion having an upper surface and a lower surface. The proximal end of the drainage tube is sloped so as to make its opening face the upper surface of the plate-shaped portion. Methods for draining aqueous humor present in the anterior chamber of an eye are also provided.