Glaucoma is an optic neuropathy characterized by cupping of the optic disc and loss of visual field. It is usually associated with increased intraocular pressure (IOP). If left untreated, glaucoma can lead to irreversible blindness. There are several types of glaucoma including open-angle glaucoma, angle-closure glaucoma, congenital glaucoma, and secondary glaucoma caused by injuries, infections, tumors or inflammation. Treatment options include medications, laser treatment, or surgery to lower IOP and prevent further vision loss. The goal is early detection and treatment to preserve sight.