[Limitations of eyeglasses and contact lens care of keratoconus].

The principal criteria for the correction of keratoconus with spectacles are the upper radii values, meridian differences and the position of the apex in relation to the fixation line. Possibilities of correction with contact lenses may be limited by optical (opacities, bad peripheral image influence etc.) and fitting factors (among others increasing ectasis, major differences in the arrow height between the apex of the cone and the surrounding cornea). Some of the problems encountered hitherto can be solved with a new "smooth flat fitting" lens.