Glaucoma is a group of eye diseases which result in damage to the optic nerve and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle (narrow angle, acute congestive) glaucoma and normal-tension glaucoma. Increased intraocular pressure causes vision loss in the affected eye and leads to blindness if not treated. The treatment is only able to stop or slow the loss of vision. This is usually associated with increased fluid pressure in the eye.
