| 摘要 |
<p>To provide a toric contact lens 10 having a prism ballast structure, wherein a center optical area 28, an annular transition area 30 surrounding the center optical area 28 determining a refractive degree, and an annular peripheral area 32 surrounding the transition area 30, are defined on a lens front surface. A shape of the lens front surface has a mirror symmetry with a vertical meridian 18 as a boundary, in such a manner that a thickness is smoothly decreased toward a lens lower end portion 26 from two maximum thickness portions 36 and 38 where the thickness of the lens is maximum, and a valley-shaped slab-off 40 is formed between these maximum thickness portions 36 and 38.</p> |
