A Sign of ageing?
We all know Benjamin Franklin, or at least we’ve come across his name at some point. Although more famously known as one of the founding fathers of the United State of America, Benjamin Franklin was also an inventor. He was, arguably one of the pioneers in the optic world. Look around and it’s really not hard to see people, especially the elderly with glasses that look like this:
Yeah, they look a bit weird, ain’t they? However, for some people they are a necessity. And those glasses have a generic name – bifocals.
Bifocals, as the name suggests, are glasses with two portions of different focal powers. Such glasses can be easily identified by what it’s called a visible ‘segment line’ that divides the lens into two distinctive portions – one for distance and the other for near vision.
In most cases, bifocals are required by presbyope (Mandarin: 老花眼) where the person struggles to see things up close as part of ageing. And this happens when the natural lens in the eye gradually loses its elasticity. When it turns out, the lenses won’t change its curvature adequately to bring close-up objects into focus on the retina.
Put it simply, think of a healthy lens as a ripped man and an old lens as a frail man. As focusing on something near requires more effort than just looking at something in the distance, a ripped man can undeniably do a better job than the old, frail man.
Presbyopia – Benjamin Franklin was no exception
Presbyopia, as it is a normal ageing phenomenon, affects everyone including Benjamin Franklin. At that time, the only solution to presbyopia was to use two pairs of glasses – one for distance and the other for near work.
Tired of carrying two pairs of glasses, Benjamin Franklin came up with a brilliant solution in 1784. Firstly, he simply halved his distance and reading lenses. After that, he placed the tops of the distance lenses and the bottoms of the reading lenses into a single frame. The end result was a single pair of glasses that caters for both distance and near work like reading. It’s known as Franklin Bifocals.
Although Franklin Bifocals weren’t cosmetically appealing in addition to the annoying reflections produced at the juncture, the invention had certainly paved the way for the advent of the more conventional, modern bifocals we see today.
Of course, with better bifocal designs such as solid and fused bifocals, Franklin bifocals are very uncommon nowadays.
Bifocals are becoming obsolete?
The bifocals market, as I would love to believe,has certainly fallen as a result of the invention of progressive addition lenses (PAL) or varifocals. Essilor, the giant lens manufacturer invented the first commercially succesful varifaocals in 1959 and they marketed them as Varilux.
In essence, Varifocals look exactly like your normal glasses. And people love the fact that there’s no segment line whatsoever because the ‘line’ as seen on bifocals can easily expose their age. I personally do not think that bifocals will become obsolete, at least not in the next few years. This is because adaptability to Varifocals is a big issue for certain people. Besides, the current prices for varifocals can easily put off some potential buyers and still, the older patients are reluctant to change in a lot of cases.
Do you wear bifocals or have you tried varifocals before? Feel free to comment what you like and don’t like about varifocals and/or bifocals! And if you are a reader from either Malaysia or Singapore, you can find more information on where you can get a comprehensive eye examination HERE.