Presbyopia correction contact lens
CA 2281121 C · Owner: Oyama, Hiroyuki · Inventors: Oyama, Hiroyuki; Miyamura, Kazuya; Sawano, Tadashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Presbyopia correction contact lens including an optical zone consisting of a substantially circular central optical portion and an annular peripheral optical portion outside the central optical portion the central and peripheral optical portions having respective different optical power values so-that the central and peripheral optical portions provide one and the other of a near vision correction region and a distant vision correction region respectively, wherein the central and peripheral optical portions provide the near and distant vision correction regions respectively, and the optical zone includes a front surface having an arcuate configuration with a substantially constant curvature …
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 August 25, 1999 and granted October 21, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 25, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 25, 2021.
- 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.