A device and method is disclosed for preventing glaucomatous optic neuropathy, an affliction of the eye. An incision is made in the scleral region of the eye and an optic nerve head shield is inserted and positioned proximate to the optic nerve head of the eye to form a pressure seal over the optic nerve head of the eye. The optic nerve head shield decreases the pressure differential across the cribiform plate preventing bowing of the cribiform plate and glaucomatous optic neuropathy.