Method for manufacturing toric contact lenses
US11207854B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2019 |
| Grant date | Dec 28, 2021 |
| Priority date | — |
| Expiry date | Jun 30, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C13/001
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing of an astigmatic contact lens having a toric portion and a thickness differential feature to provide lens orientation on eye portion such that said thickness differential causes the toric portion of the contact lens to properly orient in the eye of the wearer. The toric lenses are manufactured by an effective process control method for cylinder power in toric lens production by determining an amount of a mold cylinder compensation which is caused by processes in a toric lens manufacturing system including tool making, injection molding, casting and curing, wherein the mold cylinder is defined as the difference in measured radius of curvature at two orthogonal directions. A control metric is established by using the amount of a mold cylinder compensation and tolerance range and reject mold out of the control limits and improve the production yield for toric lens manufacturing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.