1. A method of constructing images of a lens of a pair of glasses from an image of the pair of glasses with an uniform background, the image being taken with a numerical acquisition device, comprising the steps of: generating a silhouette of the lens by clipping the lens in the taken image; generating a digital model of the lens by a processor configured to: project the silhouette on a 3D surface of the digital model; adjust a surface of degree 2 to the projected silhouette; cut the adjusted surface according to the projected silhouette; extrude the adjusted surface from the 3D surface to obtain a desired thickness of the lens; and apply a texture on the digital model of the lens, said texture depends of the angle of view of the lens.