title: Increasing the range of the keratometer.
abstract: How can the ophthalmologist perform keratometry on a patient whose corneal curvature exceeds the limits of the keratometer? A technique for extending the range of the keratometer to test such patients, e.g., those suffering from keratoconus or corneal plana, is presented.
mesh_terms: D003315:Cornea / Q000002:abnormalities; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis; D007909:Lenses; D009885:Ophthalmology / Q000295:instrumentation*