The glaucoma is a disease of the eye which comes with a temporary or chronic raised intraocular pressure. It leads to an erosion of the excavatio papillae nervi optici (see yellow dent) which can atrophy in the progress and brings scotoma as well as deteriorated eye sight. When executing ophthalmoscopy (see picture), the papilla seems pale, and the vessels seem bent. It can be caused by obstruction of Schlemm’s canal (primary glaucoma) or a complication in the cause of another eye disease (secondary glaucoma). The aqueous humor (Humor aquosus) is secreted into the posterior chamber of the eye and circulates through the pupil into the anterior chamber of the eye. In the angulus iridocornealis it is resobed physiologically by the so-called Schlemm’s canal and into the trabecular meshwork (Plexus venosus sclerae). If the angle is obstructed, the aqueous humor accumulates and thus the pressure increases. The scotoma usually begins pericentrally (see black edge).