Improvements in or relating to the manufacture of adjustable focal length lenses

A variable focal length lens 90 has superposed lens elements 180, 280 having complementary cooperating optical surfaces 182, 281. A coupling member 133 of the coupling mechanism is fixed relative to the first lens element and the lens elements are moved to a configuration in which the lens elements are superposed along an axis of viewing through the lens elements. At least one optical property is measured along the axis of viewing and the lens elements are aligned with respect to one another. The coupling member is fixed to the rear lens element 280 at a position within the opening or recess corresponding to a relative disposition of the lens elements at which the at least one measured optical property is within a predetermined range of values indicative of the lens elements being suitably aligned. Also, a coupling portion of the coupling mechanism is embedded in a first region of one of the lens elements, the first region comprising a first material such as an adhesive, and wherein the first region is surrounded by a second region, the second region comprising a second, different material such as a different adhesive.