A drainage apparatus and method to reduce intraocular pressure in an eyeball that includes an anterior chamber having aqueous humor disposed therein, a cornea and a surrounding marginal limbus by which the cornea is continuous with a scleral layer and a conjunctival layer disposed on an exposed surface of the eyeball and under eyelids, the apparatus comprising an inlet assembly configured to be disposed at the anterior chamber of the eyeball, an outlet assembly configured to be disposed at the external surface of the eyeball, a tube extending between the inlet and outlet assemblies and configured to promote fluid communication between the inlet and outlet assemblies, and a control means disposed within the outlet assembly for controlling a flow of aqueous humor through the tube from the anterior chamber of the eyeball to the external surface of the eyeball, and for preventing bacterial infiltration into the anterior chamber.