Open-angle glaucoma

Illustration showing open-angle glaucoma

Normally, fluid (aqueous humor) in the eye flows freely through the anterior chamber and exits through the drainage system (trabecular meshwork). If that system is blocked or isn't functioning well, the pressure inside the eye (intraocular pressure) builds, which in turn damages the optic nerve. With the most common type of glaucoma, this results in gradual vision loss.