Normal intraocular pressure ranges between 5-21 millimeters of mercury (mmHg) with the average value at 15 mmHg. The intraocular pressure can vary during the day (diurnal variation) and depending on personal factors. Ocular hypertension increases risk of glaucoma, but not every ocular hypertension patient has glaucoma. It depends on whether the optic nerve is damaged or not. Ocular hypertension patients are categorized as a glaucoma suspect. That is why this group of patient needs to see and follow up with an ophthalmologist and take good care of themselves on a continual basis.