1. A method of measuring the curvature of a surface of an object, comprising: (a) illuminating the object surface with a light pattern having a known size to produce a virtual reflected image from the optical surface; (b) measuring a size of the virtual reflected image produced by the optical surface from the light pattern; (c) calculating a curvature of the optical surface from the known size of the light pattern and the size of the virtual reflected image; and (d) adjusting the size of the light pattern; and (e) repeating steps (b) and (c) for the light pattern having the adjusted size.