Carl Zeiss Vision International Gmbh

Michael Gall

Angela Nolan

Ray Steven Spratt

Philipp Ellinger

A finished uncut spectacle lens has a curved front surface including an optical bowl with a convex curvature and a peripheral lentic zone surrounding the optical bowl. The curvature of the curved front surface in the peripheral lentic zone is flatter than in the optical bowl. The optical bowl size is large enough that a lens filling the entire frame can be glazed from it. The inclusion of a flatter peripheral lentic zone enables a larger diameter of the finished unglazed lens (d) with larger edge thickness than would be possible if the same back surface was cut on a semi-finished blank having a uniform spherical front, without compromise to the finished lens center thickness. In addition, a method of manufacturing such a spectacle lens and a semi-finished lens blank used in the method are provided.

Method of manufacturing a spectacle lens, finished uncut spectacle lens and semi-finished lens blank

A manufacturing method for manufacturing a spectacle lens is disclosed. The method includes: obtaining prescription data descriptive of an ophthalmic prescription of a user in the plus prescription range; obtaining frame data descriptive of a perimeter of a spectacle frame in which the lens is to be mounted; providing a lens blank having a convex front surface and a back surface; determining a final cutting surface to be machined on the back surface of the lens blank in a final cutting phase; and determining an intermediate cutting surface to be machined on the back surface of the lens blank in an initial cutting phase. Further, it is provided that the intermediate cutting surface is different from the final cutting surface; and the final cutting surface comprises a prescription zone in which the final cutting surface together with the front surface fulfills the ophthalmic prescription of the user.

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Aberfoyle Park, Australia

Michael Gall