In this clinicopathological case report on a 27-year-old man suffering from mucopolysaccharidosis (MPS) type VI-A (Maroteaux-Lamy), histologic findings in both eyes, and histologic and ultrastructural findings in a keratoplasty button are presented for the first time in the German literature. Type VI-A is a very rare type of MPS, very benign as regards mental development. It results in a typical corneal opacification due to massive accumulation of mucopolysaccharides in all corneal layers. The opacification was treated successfully in one eye by penetrating keratoplasty. Thickening of the sclera and the optic nerve sheaths was demonstrated for the first time by computer-assisted tomography. Additionally, bilateral atrophy of the optic nerve, probably caused by elevated intracranial pressure, was found. The differential diagnostic differences between this and other types of MPS and the reason for the two cardinal symptoms (corneal opacification and optic atrophy) are discussed in extenso, and a review of the literature is given.