Back to results
US 4,719,657 AGranted
Method of forming iris variegation patterns on contact lenses
AssigneeBausch & Lomb Incorporated
InventorRajan Bawa
Life of this patent
Estimating the term…
Abstract
A tinted soft contact lens such as a hydrated hydrogel lens having a variegated iris pattern is prepared by forming an iris pattern on the lens with a viscous paste which can contain an unoxidized vat dye. The lens is treated with a developer solution to obtain a tinted lens having an iris pattern which can be clear or different in color or in hue from the surrounding iris area.
Claims6
A method of forming a dyed pattern in the iris area of a hydrated hydrogel contact lens which comprises:
- forming a viscous paste which comprises an aqueous liquid, a thickening agent and a vat dye in its reduced state,
- applying the paste in the form of a pattern to the surface of a soft, resilient, impervious rubber or plastic pad,
- pressing the pad into contact with a portion of an annular area surrounding the pupilar zone in the iris area of the lens to transfer the paste in a pattern to said annular area,
- treating the lens with an aqueous solution of a different reduced vat dye,
- treating the lens with a vat dye developing solution to form on the lens a dyed pattern in the iris area and a contrasting background tint in areas not covered by the print paste, and
- thereafter washing the lens to remove any remaining paste and developer.
3 more elements
A method of forming an undyed pattern in the iris area of a tinted hydrated hydrogel contact lens which comprises:
- forming a viscous paste which comprises an aqueous liquid and a thickening agent and is free of vat dye in its reduced state,
- applying the paste in the form of a pattern to the surface of a soft, resilient impervious rubber or plastic pad,
- pressing the pad into contact with a portion of an annular area surrounding the pupilar zone in the iris area of the lens to transfer the paste in a pattern to said annular area,
- treating the lens with an aqueous solution of a reduced vat dye,
- treating the lens with a vat dye developing solution to form on the lens a background tint in areas not covered by the paste, and
- thereafter washing the lens to remove paste and developer, and obtaining a lens with an undyed pattern and a surrounding tinted area.
3 more elements
Dependencies are inferred from the claim text.