Lyon v. Bausch & Lomb, 224 F.2d 530 (1955)
United States Court of Appeals Second Circuit.
Argued April 6, 1955.
Decided June 20, 1955.
Lyon added step of heating in a vacuum to coat clear glass with a protective coating.
Sustained patent from 1942: will not change things retroactively
Started concept of "non-obviousness":
If there has been a need for a long period of time and no one has found a solution, then it is non-obvious and therefore patentable
"The most competent workers in the field had for at least ten years been seeking a hardy, tenacious coating to prevent reflection; there had been a number of attempts, none satisfactory; meanwhile nothing in the implementary arts had been lacking to put the advance into operation; when it appeared, it supplanted the existing practice and occupied substantially the whole field. We do not see how any combination of evidence could more completely demonstrate that, simple as it was, the change had not been "obvious * * * to a person having ordinary skill in the art"