Process of spincasting a compound contact lens
US5300262A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1992 |
| Grant date | Apr 5, 1994 |
| Priority date | — |
| Expiry date | Oct 29, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2011/0033
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The process of reproducibly making a wholly spuncasted, non-truncated, ballasted soft contact lens containing a compound anterior surface. The process comprises spincasting a polymer-forming, lens forming monomeric mixture in a cavity mold having a surface that is offset to allow for generation of a prismatic ballast, a compound curvature and a central axis that is symmetrical to the peripheral edge of the lens being formed. This is done by rotating the monomer mixture in the mold whereby the mixture replicates the mold's surface while at the same time undergoes polymerization and forms a prismatic lens with the central axis of its posterior surface symmetrical to its peripheral edge, a corneal bowl free of the compound curvature and possessing a thickness profile that is asymmetrical with respect to its geometric center.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.