Shaping an ophthalmic lens

A method for use with a base eyeglasses lens, the method comprising:

• forming an additional lens from an amorphous thermoplastic polymer, such that the additional lens has an optical design;
• changing a curvature of the additional lens such that the curvature of the additional lens conforms with a curvature of the base eyeglasses lens, without causing a loss of the optical design of the additional lens, by:
• heating the additional lens to a temperature at which a Tan Delta of the amorphous thermoplastic polymer is between 0.2 and 0.8, where the Tan Delta of the amorphous thermoplastic polymer is measured according to ASTM D 5023;
• and
• while the additional lens is at said temperature at which the Tan Delta of the amorphous thermoplastic polymer is between 0.2 and 0.8, shaping the additional lens, such that the curvature of the additional lens conforms with the curvature of the base eyeglasses lens;
• and
• subsequently, adhering the additional lens to the base eyeglasses lens, the optical design of the additional lens being such that, upon being adhered to the base eyeglasses lens, the adhered base eyeglasses lens and the additional lens provide a combined lens having a desired optical prescription.