The present invention relates to a method and a device for machining glass-lenses using a glass-lens machining apparatus with computerised numerical control. The method of the present invention comprises the following steps: introducing opto-metrical data relating to the glasses support into the computer of the apparatus control device which is provided with a host connection; introducing into the computer the data corresponding to the shape of a selected rim for glasses; introducing into the computer data about the material of the non-machined lens; calculating the required diameter of the glass-lens and displaying the result; introducing a non-machined lens into the apparatus; optionally calculating, e.g. in the host computer, the gradient of a bevel, groove or bezel on the shaped glass-lens according to the data introduced or to the front or back curves which are inherent to the existence of surfaces; and carrying out the computerised numerical-control machining of the non-machined lens.