This document provides an overview of glaucoma, including its anatomy, physiology, types, diagnosis, and treatment. Glaucoma is caused by damage to the optic nerve from increased intraocular pressure, which is usually due to an imbalance between the production and drainage of aqueous humor in the eye. There are two main types: open-angle glaucoma, which accounts for most cases, and closed-angle glaucoma, which has a sudden onset. Treatment aims to lower intraocular pressure and prevent further vision loss through medical approaches like eye drops, laser treatments, or surgeries like trabeculectomy that improve aqueous humor drainage.