Progressive lens with reduced distortion
AssigneeOpticlear Inc.
InventorBernard B. Fresco
Life of this patent
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Abstract
A progressive spectacle lens design has clear focal properties in the entire lens, and progressive variation in focal properties from the center of the lens down into a reading area. All current conventional progressive lenses have areas of distortion to the side of the reading area. The present invention provides undistorted optical viewing throughout the entire lens, although the focal length varies.
Claims16
A multifocal ophthalmic lens having a distance optical center, comprising:
- a first portion having first focal properties, said first focal properties being substantially constant throughout said first portion;
- and
- a second portion having second focal properties extending downwardly from a location adjacent the distance optical center and having a focal length that varies progressively downwardly in said second portion;
- and
- two regions on either side of said second portion, each of said regions having focal properties selected to avoid optical distortion.
A method of making a multifocal ophthalmic lens for use by a wearer with a field of view containing one or more critical regions for potential visual discomfort, the method comprising the steps of:
- producing a long-distance lens piece having a peripheral edge;
- producing a progressive lens piece having a peripheral edge;
- joining said long-distance lens piece and said progressive lens piece along a portion of said peripheral edges, such that said progressive lens piece is substantially outside said critical regions.
Dependencies are inferred from the claim text.