A system that can analyze and modify a point map file corresponding to a lens design is described. The lens design is optimized to meet a patient's ophthalmic prescription. However, a digital surfacing machine may not be physically capable of producing on a lens blank a lens curvature required by the prescription and defined by the point map file. The system takes into account limitations of physical characteristics of the digital surfacing machine, such as the diameter and speed of movement of the cutting tool, and modifies the point map file so that the digital surfacing machine can produce the lens curvature on the lens blank.