Granted Patent
Utility
US 4,940,762 · App. 06/769,847
Oxygen permeable lens with hydrolyzable silicon group
Inventor:
James Powell
Patented Case
View Patent ↗
Granted: Jul 10, 1990
Filed: Aug 26, 1985
Inventor
James Powell
Assignee (at issue)
Pilkington Visioncare Inc.
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.