Patti S. is a member of VSP's Ophthalmic Services team.
Conventional ophthalmic lenses might be described in many ways, depending on a person’s point of reference. Many years ago, while working as a sales representative for a progressive lens company, it was not uncommon to hear people refer to my wares in terms suggesting they were not of the “conventional” variety. Progressive lens designs, after all, employed sophisticated engineering techniques to create a lens with a gradual increase in plus power so that my lifeblood, the presbyopic population, could enjoy distance to near vision (and everything in between) without lines. This was still considered cutting edge then, but now generally regarded as “conventional.”
In spite of the fact that progressive addition lenses have been commercially available since the 1950s, with the first patents appearing in the early decades of the 20th century, they were just gaining noticeable use in the 1980s and 90s. At this time, the technology used in their design rendered this category of lens a genuine visual benefit versus a mere cosmetic enhancement. Nevertheless, the model on which progressive designs were created was based on a molded blank containing the aspheric surfaces that induce power change with a back surface traditionally ground to create the actual prescription. Researchers developed better ways to manipulate the front surfaces through the years through refinements and advancements in engineering technology, but the basic model remained the same.