Tonometry (IOP)

Tonometry is a test that measures the pressure inside your eye, which is called intraocular pressure (IOP). This measurement can help your doctor determine whether or not you may be at risk of glaucoma. A person with elevated IOPs, suspicious optic nerves and strong family history of glaucoma is referred to as a glaucoma suspect. Vision loss occurs when the eye pressure is too high and damages the optic nerve. 

Any damage as a result cannot be reversed. The peripheral (side) vision is usually affected first then the central vision decreases if not treated. The changes in vision may be so gradual that they are not noticed until a lot of vision loss has already occurred.