Glaucoma is a group of eye diseases that damage the optic nerve and cause vision loss. It is often associated with an abnormally high pressure inside the eye. The most common type is open-angle glaucoma, which has no symptoms until significant vision is lost. Risk factors include family history, age over 40 for African Americans and 60 for others, high eye pressure, thin corneas, and certain medical conditions. Treatment aims to lower eye pressure and prevent further vision loss through eyedrops, oral medications, laser treatment, or surgery. People with glaucoma require lifelong management to preserve their remaining sight.