Glaucoma is a group of eye diseases characterized by damage to the optic nerve. In its early stage, glaucoma may present few or no symptoms and can gradually steal sight without warning, In fact, most people affected by glaucoma do not know they have it. If left undetected and untreated ,glaucoma can lead to blindness.

One of the major risk factor for glaucoma is elevated pressure (IOP), or pressure inside the eye. A healthy eye produces fluid, called aqueous humor, at the same rate at which it drains. High pressure result when the drainage system is blocked and the fluid cannot exit at a normal rate. This increased IOP pushes against the optic nerve causing gradual damage, which may result in vision loss,usually starting with the peripheral, or side vision. Increased eye pressure is often associated with gradual damage to the nerve fiber that make up the optic nerve. IOP is currently the only treatable risk factor for glaucoma.