摘要 |
Apparatus and methods to modify the intensity distribution of a beam of radiation, such as a laser, and for eroding surfaces with predetermined shapes. A rotatable mask is formed with one or more apertures that have a geometric spiral shape originating substantially the center of rotation on the mask. The mask is insert to the beam for modification of the intensity of that beam, and additionally to form the desired etch pattern on a target surface. In a preferred embodiment, the invention is useful for performing kerotoplasty or keratomileusis. |