A system and method for diagnosing the onset of keratoconus in a cornea requires subjecting the cornea of an eye to a pressure that changes its shape. A topography of the cornea's anterior surface (possibly, the posterior surface also) is mapped. The mapped topography is then fitted on a mathematical model of the cornea. Measurements corresponding to biomechanical parameters in the cornea are then taken from the model. Next, a computer is used to evaluate the biomechanical parameters to diagnose whether the cornea is keratoconic.