A case of corneal opacities in a leukemic patient with an M-component in the serum proteins is presented, and a comparison is made to patients with granular corneal dystrophy Groenouw type I. The corneal deposits associated with the two conditions may appear identical with slit-lamp biomicroscopy. Granular dystrophy patients, however, show a normal serum immunoglobulin pattern in contrast to patients with paraproteinemic crystalline keratopathy. The two entities can therefore be distinguished from each other by a serum electrophoresis.