Method of manufacturing toric single vision, spherical or aspheric bifocal, multifocal or progressive contact lenses
US5598234A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1994 |
| Grant date | Jan 28, 1997 |
| Priority date | — |
| Expiry date | Mar 23, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/20
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for making a finished aspheric single vision, spherical or aspheric bifocal, multifocal or progressive addition contact lens includes the step of fitting a patient requiring a near correction with a single vision spherical or aspheric contact lens for optimal distance vision and comfortable fit. If desired, the patient is then over-refracted to determine the required near correction to be embodied in the contact lens. A portion of the optic corresponding to the center location of the pupil is marked on the convex side of the optic to form an optical preform. In some instances, the lens may not stabilize on the cornea to a suitable degree. Thus, it is often desirable to stabilize the contact lens, either prior to placing the lens on the patient or after rotation is observed on the cornea of the patent. Observation of rotation on the patient's cornea is enhanced by means of the mark that is used to designate the center of the patient's pupil. The optical preform is removed from the eye of the patient and the concave side of the optical preform is marked at a position corresponding to the mark on the convex side that denotes the center of the pupil. The mark disposed on the c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.