The progressive lens which is designed to provide clear vision at all distances for presbyopes, those who have lost the ability to focus at near, which occurs from 40 onwards, was designed by a British optometrist in 1905.
While the concept had merit, the original design had so many blurred zones, it was never used in practice. A French company designed the first widely available lens the 1960s. While a significant advance, it nevertheless still suffered from major peripheral distortion with only a few patients wearing it successfully.
In the 1990s a number of companies released improved designs which led to greater success with progressive lenses which began to replace bifocals as the lens of choice for presbyopes. Since then, major design improvements have resulted from computer technology and advanced lathes which can generate extremely complex curves reducing the peripheral distortion inherent in ALL progressive lenses.
As it has not been possible to eliminate all the blurred zones, multiple designs are available, some of which benefit distance vision while others favour close work tasks.
Fortunately, while none of the designs provide a perfect optical solution, the brain in many patients is able to adapt to the imperfect image providing what appears to be natural vision for successful wearers.
However, not all patients are suitable because of their expectations, motivation or visual environment. As such, it is imperative that the optometrist assess the requirements and other factors to determine the lens with the best chance of success.
