摘要 |
<p>A method for designing a surface of a multifocal optical element, such as a progressive spectacle lens, includes the steps of partitioning a region into triangles, (τi) defining a set of functions, each representing a portion of the surface (li) over one of the triangles (τi), and optimizing the functions. A further embodiment includes the steps of partitioning a region into polygons (200), and defining a set of functions, each representing a portion of the surface over one of the polygons (202). Continuity constraints for values of the functions and values for the first derivatives of the functions at boundaries of the polygons are dictated. Continuity constraints for values of the second derivatives of the functions at boundaries of the polygons are not required. The functions are optimized subject to the dictated continuity constraints.</p> |