Granted Patent
Utility
US 5,408,281 · App. 08/053,122
Multifocal contact lens
Inventor:
Xiaoxiao Zhang
Patented Case
View Patent ↗
Granted: Apr 18, 1995
Filed: Apr 26, 1993
Inventor
Xiaoxiao Zhang
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.