Normal eye pressure ranges from 12 to 22 millimeters of Mercury (mm Hg), according to the Glaucoma Research Foundation. While a pressure exceeding 22 mm HG does not alone cause glaucoma, it does constitute a significant risk factor.
Persons diagnosed with high eye pressure are encouraged to undergo regular comprehensive dilated eye exams to check for signs of the onset of glaucoma. Vision loss occurs when the eye pressure is too high for the specific individual and damages the optic nerve, states the Glaucoma Research Foundation. Other factors that place patients at an increased risk of the disease include thinness of the cornea and abnormal optic nerve anatomy, according the National Eye Institute.