Abstract: Method for calculating an ophthalmic lens comprising [a] calculating and constructing a computational model of an initial lens with a given prescription, [b] calculating the three sections of the optical path traveled by rays using the computational model, [c] determining the first surface of a lens equivalent to the initial lens, and [d] calculating the second surface of the equivalent lens by plotting the rays through the equivalent lens and determining their point of intersection with the second equivalent surface. Each ray has an equivalent optical path equal to the initial optical path, or has at least one of the sections of the equivalent optical path equal to the corresponding section of the initial optical path. The equivalent lens thus calculated is the ophthalmic lens that is the object of the invention.