Granted Patent
Utility
US 5,166,711 · App. 07/544,629
Multifocal ophthalmic lens
Inventor:
Valdemar Portney
Patented Case
View Patent ↗
Granted: Nov 24, 1992
Filed: Jun 27, 1990
Inventor
Valdemar Portney
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.