Abstract: An apparatus and method are provided for simulating a predicted post-operative topography of a cornea of an eye based on a pre-operative topography of the cornea and a proposed laser ablation procedure. A digital data processing system receives data defining a pre-operative topography of the cornea as a function of location and obtains parameters of the proposed laser ablation procedure from which the digital data processing system can determine the amount of cornea expected to be ablated as a function of location on the cornea. Based on the data and the parameters, the digital data processing system produces an output representing a simulated post-operative topography of the cornea as a function of location.