The invention relates to an ocular implant for treating glaucoma. The problem addressed by the invention is to make it possible to drain aqueous humor from the anterior chamber of the eye into the subconjunctival or suprachoroidal space in order to lower the intraocular pressure in glaucoma cases. The device is to do away with the drawbacks of known valve mechanisms and should be economical to produce. In order to solve said problem, the glaucoma drainage implant is composed of an elongate, hollow main member in which a flow-limiting membrane is arranged in the inflow region.