Inclusion Criteria:  Clinical diagnosis of normal tension glaucoma by a fellowship trained glaucoma specialist, Clinical diagnosis of a disc hemorrhage diagnosed by a fellowship trained glaucoma specialist, Must be able to swallow water Must be able to be positioned to allow accurate measurement of the Intraocular pressure with a slit lamp mounted Goldmann applanation tonometer Must have a smooth corneal surface to allow for accurate Goldmann application tonometry measurement Outpatient A sufficient level of education to understand study procedures and be able to communicate with site personnel  Exclusion Criteria:  History of refractive surgery, Active ocular infection, Pregnancy, Cardiac or renal diseases, history of urinary retention, Corneal abnormalities preventing reliable IOP measurements, Previous trabeculectomy or glaucoma shunt surgery, Previous laser iridotomy, Cognitive impairment or language barrier preventing ability to provide an informed consent.