Granted Patent
Utility
US 4,898,461 · App. 07/366,319
Multifocal ophthalmic lens
Inventor:
Valdemar Portney
Patented Case
View Patent ↗
Granted: Feb 6, 1990
Filed: Jun 14, 1989
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.