Abstract: A process and device for shaping surfaces by laser machining and which are used for photorefractive keratectomy and shaping contact lenses. The shaping is performed in stages so that after any interruption in the process, a complete partial correction of the entire surface is obtained. A computing unit receives data from input units and directs data to a block generator which associates laser machining coordinates to enable the removal of individual surface layers. A sequence generator gathers the data generated by the block generator into blocks which correspond to an individual ablation areas, and orders the blocks into sequences. A block sequence transmitted by the sequence generator acts upon a laser beam deflector and beam shaping unit such that the complete partial correction of the surface is obtained for each block sequence. A central processor coordinates control of the laser, the beam shaping unit and the laser beam deflector.