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US 8,128,222 B2Granted
Multifocal diffractive contact lens with bi-sign surface shape
OwnerValdemar Portneyinventor
Life of this patent
Estimating the term…
Abstract
A contact lens for placing over the eye is described. The lens has at least one non-spherical shape surface configured with bi-sign profile to maintain lens optical advantage as compared with equivalent far power spherical lens within common clinical condition of lens movement over the cornea of the eye.
Claims7
A diffractive multifocal optic of a contact lens comprising:
- a front and a back surface, one of the front and back surfaces being a refractive surface and another of the front and back surfaces being a diffractive multifocal surface;
- and
- at least one of the refractive surface and a base surface of the diffractive multifocal surface comprising bi-sign shape non-spherical surface with at least two largely annular regions within one optical zone, one of the two region being configured for producing a longitudinal ray aberration of a different sign from another of the two regions.
Dependencies are inferred from the claim text.