| 摘要 |
An ophthalmic lens has a complex surface with an optical centre, a fitting cross (FC) situated 4 mm above the optical centre, a meridian having a power addition between reference points in far vision (FV) and in near vision (NV). The complex surface has a mean-sphere difference normalized to the addition on the meridian, between the geometric centre of the lens and the control point in far vision, less than or equal to 0.1; a progression length less than or equal to 14 mm; a rebound of the sphere quantity normalized to the addition on a circle with a radius of 20 mm centred on the geometric centre of the lens less than 0.11, and a maximum slope of the sphere variation normalized to the addition along the meridian comprised between 0.9 and 0.11 mm<SUP>-1</SUP>. The lens is suited to broadened far vision with a good accessibility to near vision. |
