other optic nerve problems are less common. optic nerve hypoplasia is the underdevelopment of the optic nerve resulting in little to no vision in the affected eye. tumors, especially those of the pituitary gland, can put pressure on the optic nerve causing various forms of visual loss. similarly, cerebral aneurysms, a swelling of blood vessel(s), can also affect the nerve. trauma, of course, can cause serious injury to the nerve. direct optic nerve injury can occur from a penetrating injury to the orbit, but the nerve can also be injured by indirect trauma in which severe head impact or movement stretches or even tears the nerve.