Mary R Howland

US Patent:

53231929, Jun 21, 1994

Filed:

Nov 18, 1991

Appl. No.:

7/793178

Inventors:

Mary Howland - Petaluma CA
Mark Porden - Petaluma CA

Assignee:

Pilkington Visioncare, Inc. - Menlo Park CA

International Classification:

G02C 702
G02C 706

US Classification:

351177

Abstract:

Fabrication of an eyeglass lens to meet a specific ophthalmic prescription is simplified by arranging back lens wafers of different sphere powers and cylinder corrections in order of the through sphere powers of the lenses that are produced by laminating each back lens wafer with front lens wafers that have the same base curve. The front lens wafers of like segment style are grouped together and include sub-groups of wafers of similar base curve which are arranged in order of add power. Each lens wafer is maintained in an individual package prior to lamination and the back wafer packages display the through sphere powers that result from laminating the wafer with different ones of the front wafers. Reference to a conventional component selection chart is unnecessary as the correct back lens wafer can be directly located from the data on the prescription and the package of the back lens wafer directs the technician to the correct front lens wafer. Verification that the correct lens wafers has been selected is provided for by a component of the front wafer package that obscures the display of through sphere powers on a back wafer package when the two packages are superimposed except for the particular through sphere power that is produced by lamination of the wafers from the two packages.