Granted Patent
Utility
US 4,553,975 · App. 06/580,398
Tinted contact lenses and a method for their preparation
Inventor:
Kai C. Su
Patented Case
View Patent ↗
Granted: Nov 19, 1985
Filed: Feb 15, 1984
Inventor
Kai C. Su
Assignee (at issue)
Ciba-Geigy
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.