A method for measuring the thickness (s) of a wall of a transparent obiect, in particular a curved object, said wall comprising: a transparent material, a proximal interface arranged between an external environment and said transparent material, and a distal interface arranged between said transparent material and said environment opposite to said proximal interface, said method providing the steps of: - prearranging a starting light radiation; - focusing (10,11,22,23) said starting light radiation obtaining an entering light radiation directed towards said wall so that said entering light radiation: - hits said proximal interface of said wall, - is in part reflected by said proximal interface, in order to generate a first reflected radiation, - crosses in part said transparent material hitting upon said distal interface and is in part reflected from said distal interface; - crosses in part in an opposite direction, after the reflection on said distal interface, said transparent material hitting upon again and crossing again said proximal interface, in order to generate a second reflected radiation; - collecting an overall exiting light radiation obtained by overlapping of said first and second reflected radiations; - analysing said exiting light radiation with spectroscopic methods and determining the thickness (s) of said wall according to interference characteristics between said first and second reflected radiations in said exiting light radiation, characterised in that said step of focusing provides obtaining said entering light radiation through a non-axisymmetric lens means (10,11,22,23) having two main meridian planes (10a, 10b) such that said entering light radiation is focused on a first virtual focus (F 1) in a first main meridian plane, and on a second virtual focus (F 2) in a second main meridian plane. - prearranging a starting light radiation; - focusing (10,11,22,23) said starting light radiation obtaining an entering light radiation directed towards said wall so that said entering light radiation: - hits said proximal interface of said wall, - is in part reflected by said proximal interface, in order to generate a first reflected radiation, - crosses in part said transparent material hitting upon said distal interface and is in part reflected from said distal interface; - crosses in part in an opposite direction, after the reflection on said distal interface, said transparent material hitting upon again and crossing again said proximal interface, in order to generate a second reflected radiation; - hits said proximal interface of said wall, - is in part reflected by said proximal interface, in order to generate a first reflected radiation, - crosses in part said transparent material hitting upon said distal interface and is in part reflected from said distal interface; - crosses in part in an opposite direction, after the reflection on said distal interface, said transparent material hitting upon again and crossing again - collecting an overall exiting light radiation obtained by overlapping of said first and second reflected radiations; - analysing said exiting light radiation with spectroscopic methods and determining the thickness (s) of said wall according to interference characteristics between said first and second reflected radiations in said exiting light radiation,