When you come into the office and your pressure is elevated we may take it several times under differing conditions of dilation to see if there is a problem. Some patient’s pressures go up as drops are put into their eyes. This is an important test for the development of glaucoma. We may test your eye pressure in several different ways, either with a pneumotonometry machine, a Tono pen which is a form of applanation tonometry, or a Goldmann applanation tonometer. All have their places and have various sensitivities and specificities. Many patients are concerned if their pressure is low. In patients with optic nerve disease it is important to keep relatively low pressure. It is important that the optic nerve be perfused. Intraocular pressure can keep the nerve perfusion down. Pressure differential between intracranial pressure and intraocular pressure is also important. Sometimes we will need to check intracranial pressure. This will require a lumbar puncture.