Ophthalmic lens
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 add...
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Main Authors | , , |
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Format | Patent |
Language | Chinese English |
Published |
14.07.2010
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Subjects | |
Online Access | Get full text |
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Summary: | 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<-1>. The lens is suited to broadened far vision with a good accessibility to near vision. |
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Bibliography: | Application Number: CN200680011385 |