For import into CAD modeling programs, such as those produced by Autodesk, Ashlar-Vellum or SolidWorks, LensForge can export the lens surfaces in Autodesk's DXF™ format.

This figure shows a lens system and traced rays, exported to DXF and imported into Google Sketchup:


The exported file contains a minimal header, and then 3DFACE and 3DLINE entities describing the shape of the lens surfaces. The surfaces are faceted for DXF export. Color information is included.