Carl Zeiss Vision International and its American subsidiary, Carl Zeiss Vision have filed a patent infringement lawsuit against Signet Armorlite. The suit alleges that Signet's line of Kodak Unique lenses and/or the way in which they are manufactured infringes a patent held by Zeiss in the USA. Signet Armorlite has responded by saying that it does not believe it has encroached on any of Zeiss' patents, and will investigate the matter further before taking its own action.