Wikipedia on Progressive lenses

[Chris Ryser]

History
The first patent for a PAL was British Patent 15,735, granted to Own Aves with a 1907 priority date. Aves' patent included the progressive lens design and the manufacturing process. However this was unlike modern PALs. It consisted of a conical back surface and a cylindrical front with opposing axes in order to create a power progression. This design was never commercialized.
While there were several intermediate steps (H. Newbold appears to have designed a similar lens to Aves around 1913), there is evidence[citation needed] to suggest that Duke Elder in 1922 developed the worlds first commercially available PAL (Ultrifo) sold by "Gowlland of Montreal". This was based on an arrangement of aspherical surfaces.
The Varilux lens was the first PAL of modern design. It was developed by Bernard Maitenaz, patented in 1953, and introduced by the Société des Lunetiers (now called Essilor) in 1959. Varilux is currently the most widely sold progressive lens brand worldwide.

http://en.wikipedia.org/wiki/Progressive_lens

[optigrrl]

Great bit of history! Thanks, Chris -

[Darryl Meister]

there is evidence to suggest that Duke Elder in 1922 developed the worlds first commercially available PAL (Ultrifo) sold by "Gowlland of Montreal". This was based on an arrangement of aspherical surfaces

This is a typical example of why you shouldn't necessarily trust the content found on Wikipedia. This progressive lens was actually designed and described by Gowlland in a series of patents (including GB 5,583), not by Duke-Elder. Duke-Elder simply described it as the first commercially available lens in his book Practice of Refraction.

It should also be noted that Gowlland's progressive lens was rather crude in design, employing a section of a paraboloid on the back surface in order to produce the progressive change in addition power. Anna Estelle Glancy, of American Optical, patented a front-surface progressive lens design in 1924 (US 1,518,405), which was actually more similar in design to the modern progressive lenses that began appearing in the 1960s, including the original Varilux and Volk's Omnifocal. I don't believe that AO ever put Glancy's lens design into production, however.

[Jacqui]

Darryl: This was being worked on when I was in Southbridge in 1970. The big problem was polishing the lens without distorting the progression.

[Darryl Meister]

This was being worked on when I was in Southbridge in 1970. The big problem was polishing the lens without distorting the progression

Yes, producing progressive surfaces with a sufficient level of quality and accuracy was the biggest challenge for early progressive lens designers. In fact, although the original Varilux was certainly not the first progressive lens ever invented, Bernard Maitenaz did invent a more practical manufacturing method for them compared to many of the earlier attempts.