METHOD FOR FORMING A COLORED IMAGE IN A SOFT CONTACT LENS USING A DIAZONIUM SALT

摘要

A method for forming a colored image in a limited area of a visioncorrective soft contact lens. In one method, the lens is soaked in a diazonium salt and then exposed to actinic light through a mask which transmits light only to the non-image area of the lens. Then, the unexposed image area is deve-loped by contact with an azo coupler. In a second method, the diazonium salt is soaked in a gel relief of the desired image configuration and contacted with the lens. The image is developed by soaking in the azo coupler. In a third method, the diazonium salt, azo coupler, and a coupling inhibitor (a pH reducing agent) are premixed and applied by the gel relief. The image is then developed by raising the image pH level as by contact with ammonia gas. Also, apparatus for precisely contacting the lens with the gel relief image. .