Patents Assigned to Igel International Ltd.
  • Colored hydrogel objects and their production-containing a water-insoluble opaquing agent
    Patent number: 4981487
    Abstract: Shaped organic polymer hydrogels, especially contact lenses, are provided with opaque or translucent coloring so as to be capable of masking effectively any underlying color, e.g. the natural color of the eye. The hydrogel may be rendered opaque by precipitation in situ of a white or yellow water-insoluble, inorganic or organic material e.g. barium sulphate or an optical brightener and then colored with a suitable dyestuff.
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: January 1, 1991
    Assignee: Igel International Ltd.
    Inventor: Nicholas M. da Costa