When it comes to technology, progress is usually a very good thing. Progressive lenses aren’t called progressive because they’re the next step in a particular kind of vision care (even though they are); rather, they’re so named because of the layout of the lens itself. To understand progressive lenses, you first need to understand a bit about the changes that occur in your eye as you age, and how we used to use corrective lenses to treat these particular issues.
Over the age of 40, you’re very likely to see your near-sighted vision deteriorate. This is a condition called presbyopia; it occurs because your eye’s lens naturally grows less flexible and thicker. Muscle fibers are also affected, which makes it hard to focus on objects that are up close. For some folks, this can be remedied with simple corrective lenses, but that’s only the case if you weren’t already nearsighted. For those who already needed glasses to see far, presbyopia poses quite the challenge; you’ll need glasses to see far, but you’ll also need glasses to see near. You could get two pairs of eyeglasses, and switch whenever you need to see near or far, but that poses its own set of problems. You need to keep both pairs at you at once, and if you ever need to see something close up, then far away in quick succession, it can be difficult.
Eyecare professionals has sought, over the years, to create a number of solutions to this challenge. The first solution they created was called a “bifocal lens”; these lenses have two focuses, one for near and one for far, hence the name. They’re a bit unsightly; you can often see the line that separates the two lens powers. There’s another potential problem with bifocals – intermediate distances. The lens shoots from near to far, so if you’re, say, reading an online blog on your computer screen, you might find that neither power is suitable.
Another solution that was attempted are trifocals; our more astute readers will have a good idea how those work. Three lens powers, one for close, one for intermediate, and one for distance, featuring the same common problem that bifocal lenses have; the various lens powers are clearly delineated by visible lines in most cases.
Progressive lenses, as you can probably guess, are the most recent solution to the problem, and they’re a good one. Progressives have multiple lens focuses; as your eye moves around the lens, you can find a variety of different focus points that will allow you to see pretty well any distance. There are no distinguishable lines, so the lenses are also more aesthetically pleasing. No lines and a greater variety of focal points make them the ideal solution for nearsighted adults who develop presbyopia; that’s pretty progressive!