A system and method of performing therapy on target eye tissue. A light source produces a beam of light, and a scanning device deflects the light beam to produce an pattern of the light beam. An ophthalmic lens assembly includes a mirror for reflecting the light beam pattern onto the target eye tissue. The mirror is rotatable to angularly align the light beam pattern to the target tissue. Control electronics control the scanning device to apply the light beam pattern onto the reflective optical element at first and second angular orientations separated by a predetermined angle RA. The predetermined angle RA is set such that light beam patterns applied to the target tissue at the first and second angular orientations, which are also angularly aligned to the target tissue through rotation of the mirror, automatically are adjacently abutting to each other on the target tissue.