A computer-implemented method for method for tracking changes in an internet-accessible document is disclosed. A through hole is defined in the base member and communicating with the recess and longitudinally and straightly aligns with the coupling crystal. The polymer carrier complex is bound to the hapten via a linker unit, strategically positioned meta to the amide or amide derivative of BAM. A head section records andor reproduces information from the storage medium rotatively driven by the drive unit. The plurality of distances can be used to determine an apex of the curved surface of the patient interface and to align the laser treatment axis with the apex of the curved surface.