This site is half a hobby site about this useful invention from Benjamin Franklin, and half a practical consumer site for helping people make smart decisions when shopping for bifocal reading glasses. With this site I’ll provide you with a little bit of the history of these clever spectacles as well some specific information to consider before you buy yourself the perfect set of bifocals.
I address a range of styles and purposes from rimless eyeglasses to computer glasses, but I will largely focus on traditional bifocal glasses for reading. I still find this classic device a utility of great function, comfort and I even find it a cozy tradition. I enjoy glancing from my wife to my reading without adjusting my eyeglasses and I am very relieved to not have to poke lenses on to my damp, delicate eyes. In other words, I’m not terribly fond of contact lenses. You may also see bifocals referred to as Executive Bifocals or Franklin Glasses.
So onwards we go. Here’s an index of this page’s content. Click on any header to skip down to a topic, then click on your browser’s back button to return to the top here. I hope you find Bifocal Reading Glasses worth your time!
- Introduction to Eyeglass Frames and Lenses
- Plastic Lenses for Bifocal Reading Glasses
- History of Bifocal Reading Glasses
- Classic Spectacles Today
While I still like the traditional term spectacles — or refer to their type with greater specificity (like “bifocals” rather than “glasses”) — many simply refer to the topic at hand as glasses or eyeglasses. These classic eyeglasses are supported by tiny pads designed to balance on the bridge of your nose while remaining secured by hooking back around your ears. For those of you who enjoy a little history, you might read more about historical models such as the lorgnette, monocle or the pince-nez.
Today’s frames are normally crafted from plastic or metal. While at one time lenses were all made from glass, today most are made from a variety of plastic and metal, often polycarbonate or CR-39.
This evolution has led to corrective eyeglasses that weigh significantly less than their glass counterparts and break far less frequently. In some cases, these plastics also provide greater optical properties, such as greater transmission of light while also absorbing more of the damaging ultraviolet light.
Specifically, some of these plastics provide a greater refraction index than glass. This empowers optometrists with greater flexibility to create accurate corrective lenses with thinner, lighter material for the same relative prescription.
The latest plastic lenses — entitled izon, may also be utilized to correct stronger problems on the surface of our eyes. These innovative lenses create more clear and accurate vision while curbing problems such as comet-tails, halos and starbursts and are especially useful in providing for safer driving at night so they can also be used as night driving glasses.
Today the most common lenses are made from a plastic called CR-39. This is due to their great resistance to scratching, their ability to remain clear while also absorbing ultra violet radiation and their very low weight. In environments where there is a greater risk of high impact, Trivex and polycarbonate lenses are most often utilized because they are very light and remarkably shatter resistant. However, these shatter-resistant lenses are not always the best bet for all circumstances because they offer poorer optics with high dispersion and a low Abbe number of 31.
Depending on the order, a number of coatings might be applied to plastic lenses. These coatings include scratch resistance, hydrophobic coatings to ease cleaning, and anti-reflective coatings with several purposes from reducing glare from a computer monitor to improving night vision.
Today most historians credit Italian Salvino D’Armate for inventing the first eyeglasses in about 1284. Almost exactly 500 years later in 1784, Benjamin Franklin developed bifocal reading glasses. This is one reason why we often see these bifocal eyeglasses referred to as Benjamin Franklin bifocals.
As the great Ben Franklin aged he began to have difficulty seeing both at a distance and up-close. After he grew weary of swapping two pairs of glasses to address his near and far sight, he developed a technique to incorporate the lenses of both types of glasses into a single frame. The up-close lens was placed at the bottom for reading while the distance lens was placed at the top to allow for quick glances at distance subjects.
From D’Armate’s invention through Franklin’s refinement to today, the design and function of eyeglass frames has greatly evolved. Early eyeglasses required being held in place by hand or a with pressure on the nose (the “pince-nez”). From these inconvenient designs Girolamo Savonarola implemented eyepieces which were held in place by material pulled over the wearer’s head and secured by a hat. Sound awkward? Indeed. Thankfully, British optician Edward Scarlett devised the modern method of temple arms passing over the ears in 1727.
While we all know these as the de facto style of eyeglasses today, in fact it took some time for them to become the standard. Many earlier styles, as well as lorgnettes, maintained popularity through the 18th century and even into the early 19th century. Read more about bifocals history: The History of Bifocal Reading Glasses
Even with the increasing popularity and functionality of laser corrective eye surgery and contact lenses, good old fashioned bifocal reading glasses remain common and well-liked by many people. Their technology has improved greatly, from precise corrective lenses to frames made with special memory metal alloys which return to their original shape after being forcibly misshaped. These frames are not only far more durable, but they’re much lighter and easier on your ears and nose than ever before. And we now have no line bifocal reading glasses and sophisticated progressive lenses with multiple prescription lenses seamlessly blended into a single piece of eye wear.
I hope this helps you better understand why bifocal reading glasses can still work for you and what to look for when you start shopping. Thank you for reading Bifocal Reading Glasses and take care!