| 摘要 |
The lens comprises an optical zone (A), an aspherical separating zone (B) and a peripheral zone (C). The curved outer surface of the lens has an optical zone (A') of the same type as the inner optical zone, an aspherical compensating zone (B') and a peripheral zone (C'). The optical zone (A') and the compensating zone (B') are designed so that the resultant of their two aspherical curves are presented to the wearer as a spherical optical surface. The curvature (4) of the outer surface is of the same type as the inner one (3), reduced in the compensating zone to a dimension (Z'), which is 2 - 20 per cent, and especially 12 per cent, of the dimension of the inner aspherical zone (Z). ADVANTAGE - More precise vision correction is achieved, permitting a large degree of asphericity of the inner curvature.
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