Granted Patent
Utility
US 4,199,231 · App. 05/934,714
Hydrogel contact lens
Inventor:
Carl Evans
Patented Case
View Patent ↗
Granted: Apr 22, 1980
Filed: Aug 21, 1978
Inventor
Carl Evans
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.