Soft toric lens for correction of astigmatism
CA 2096706 A1 · Owner: Mercure, Robert · Inventors: Mercure, Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A toric contact lens for correction of astigmatism comprises a concave posterior surface to be applied to a wearer's eye, and a convex anterior surface symmetrical about an horizontal plane of symmetry. The anterior surface comprises a central optical zone, and a pair of upper and lower peripheral prismatic zones situated outside the central optical zone and symmetrical about the horizontal plane of symmetry. Each prismatic zone defines an apex along the peripheral edge of the lens, and the lens has in, the region of each prismatic zone, a thickness that gradually increases from this apex toward the central optical zone whereby sliding movement of the eyelids on the prismatic zones pushes …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 20, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.