| 摘要 |
<p>The invention relates to equipment for the correction of astygmatism by modelling of the corneal surface by means of photo-ablation. A laser beam produced by an excimer laser is used, which is masked by a special mask (1) in such a way that, at each application, a pre-established surface of the cornea (3) is struck, from which cornea (3) a very thin uniform layer of tissue is removed. Two symmetically sliding mask elements (21) from a variable polygonal aperture. A central variable masked area may be created using a pivotable central mask element. <IMAGE></p> |
