Diving Into History
Designer glasses have become a new trend in the 21st century, but did you know that ancient Greeks were the first to begin studying eyes? Their curiosity of how magnification worked led them to conduct studies on individuals who experienced vision problems. Alhazen, An Arabian scientist who lived in the eleventh century studied the bending (refraction) of light and the connection between the brain and the optic nerves. It wouldn’t be until the thirteenth century that Vitello, a Polish scientist, would first begin connecting the pieces and understanding that the shape of a lens could be used to control the focus of rays of light.
In 1257, English friar Roger Bacon became so knowledgeable in various aspects of science that he was locked away by the monks of his order due to their growing suspicion of the knowledge that he had accumulated. While locked away, Bacon sent Pope Clement IV a few magnifying lenses for reading purposes. Oddly enough, the same monks who locked Bacon away realized that they also needed his magnifying glasses. During this time, Monks spent their days pouring over copy work and detailed manuscripts which likely caused a significant strain on their eyes.
Though lenses were proven to work and made the lives of popes and monks significantly better, it would take several more centuries before the invention of the device that allowed spectacles to sit on the bridge of the nose to appear. The first eyeglasses were simple unframed lenses that had to be held in front of the eye to achieve the desired effect. The next iteration of eye glasses came in the form of two lenses mounted together on a half frame that could also be held by a single hand (a notable improvement on the previous model). As lenses became more popular, style became more of a factor in how they were worn. It wasn’t uncommon to find spectacles attached to hats or tied around the head with leather or ribbon bands.
The jester of Henry VIII, Will Somers, wore a suit of armor with spectacles attached to his metal helmet. Lenses even found themselves into artwork when the painter El Greco portrayed Cardinal Nino de Guevara sporting glasses with cords that looped over his ears (much like that nerdy kid you likely made fun of in school). The seventeenth century brought an interesting design known as the forehead frame in which a metal band with metal frames attached to them encircled the head. Above all stylish choices made by lens wearers came the more common design where two lenses on a frame straddled the lower part of the nose. Lightweight materials were used to lessen the weight on the nose. It was also used to reduce pinching.
The first example of glasses becoming a popular trend was in the court of Spanish King Phillip V and Queen Marie-Louise (around 1701) where every one of the Queen's 500 ladies-in-waiting sported tortoise-shell frames due to their light weight material. Style wasn’t just reserved for Queen Marie-Louise’s chic spectacle wearing ladies-in-waiting. Bridge pieces and lenses were often the target of stylistic changes. Lenses were mounted on watches, fans, and even walking sticks. The rich often had their frames crafted from gold and other precious metals. Artists were employed to decorate frames with unique designs.
Glasses that sat on the bridge of the nose weren’t the only choices to fashion conscious consumers. There was also the monocle, the lorgnette (a pair of lens with a nose bridge and a single handle on one side), scissors glasses (two eyepieces that were mounted on a hinged handle that was held up in front of the nose), and perspective glass (a single lens suspended from a ribbon that allow its users to enhance vision from a distance). In 1728, Edward Scarlett of London finally created frames for temples. This new revolutionary design allowed for clamps to firmly grip the temple which in turn held glasses that sat on the nose more securely to the face. Each end of the temple piece had a loop that allowed an individual to tie a ribbon around their head. In 1880, the temple design was curved so that they would extend and fit firmly behind the ear.
Early American colonies also used spectacles imported from overseas. Spectacles were used for improving sight, but fashion was still as important to the colonies as it was all over the world. The eyeglass fashion trend in the colonies was called the Oxford, which consisted of nose glasses that allowed more comfort due to the more elastic and wearable bridge. Oxfords were so popular that even presidents Calvin Coolidge and Teddy Roosevelt sported a pair during their presidential terms. When the 1900s arrived, lenses housed in steel frames became all the rage. Less expensive glasses were created from a rubbery plastic-like material called gutta-percha. Horn-rimmed and Tortoiseshell were popularized during the 1920s and 1930s. In the second world, war servicemen were issued sunglasses and steel-framed spectacles and sunglasses by the millions.
Eyeglass frames made its most dramatic transformation during the twentieth century. The plastic industry had just begun a boom, and they would soon enter into a lucrative relationship with eyeglass manufacturers. The lightweight properties of plastic allowed manufacturers to develop bifocals, trifocals, and quad trifocals which were used to correct wider ranges of sight issues. Also, plastic lenses were cheaper and easy to design to match fads, moods, and styles. With the rise of more affordable spectacles came the rise of sunglasses.
When it comes to designing frames, eyeglass manufacturers may keep on their own staff or even utilize the unique outside skill sets of consultants. In many cases, these experts include individuals who command their own fashion lines. They tend to specialize in designing eye wear that changes with clothing trends. The designer name attached to the brand of frames is essential if a manufacturer hopes to make sales. Fashion-conscious buyers might buy multiple pairs of glasses and sunglasses if they were branded with the name of a popular designer. There are many trends for eyewear which include frames with light or dark colors, thin or thick frames, and frames with unique designs. Even frames for children are designed with fashion in mind.
Aside from fashion trends, standards have become common place in frame designs. You’ll find eye size, bridge size, and other like measurements to ensure that the wearer is matched with the most accurate sized frame. The bridge size is of particular importance because it takes into consideration the thickness of the nose. Not every face is the same, thus measurements have to be exact (or at least close) so that the wearer is as comfortable as possible.
The Manufacturing Process
Die-Cutting Plastic Frames
The design is only the first part of the process. After that step, steel is used to make die, and is then fitted into a blanking machine (a device that creates blanks out of cellulose-acetate sheets). The edges of the end product are sharp in nature. The dies have a rod that protrudes outward that is used to remove the punched fronts where the lenses are fitted. The acetate sheets are stored in a storage area where they’re brought to the blanking room where they’re placed into ovens, typically small in size, that are heated to about 180° F (68° C). This is done to soften the plastic. When the sheets become sufficiently soft, they’re placed into a blanking sheet where they’re exposed to several tons of pressure and cut to produce a blank.
It takes a series of operations to finish a blank frame. A router is used to cut the grooves that hold the frame. An aluminum holding fixture is used to hold a frame in place which consists of two pieces. The fixture is then tightened around the frame and pressed against the router blade. Industry standards dictate that grooves cut into frames are 0.16 in (0.41cm) wide. In the instance where thicker lenses are required, the edges are shaved down to fit the routered grooves.
At this point, the frames are run through two different abrasive machines to smooth away any rough edges. Each machine has a specific purpose. One machine is used to smooth out the frame that rests on the cheek. The second machine smooth’s out the area of the frame that sits near the nose.
The temples are the two curved side arms that fit around the ears. Just like with the previous section the temples also go through a process in which they’re punched out of acetate sheets with blanking dies. Typically, temple length range around 5 to 6 inches (12.7 – 15.2 cm). In most cases, they’re cut from the same or complementary materials to match the fronts. Depending on the style of the frame, the temples may have various shapes such as being either round in shape or flat with angular edges. The next step involves heating both the temples and a narrow strip of steel called core wire. The core wire is inserted into the center of the now softened temple when the temperature reaches appropriate levels. The reason that certain types of non-prescription sunglasses tend to be weaker than other higher quality glasses is that they may not have been made with a core wire.
Frames don’t automatically attach to temples without a bit of modification. To ensure that temples attach to their frames, the upper corners of the frame have small slots cut into them. A partial piece of a metal hinge is placed into the cuts, and both the partial metal hinge and the frame are inserted into a capitron machine. From there the machine takes care of the rest. The capitron machine causes ultrasonic vibrations to reverberate the partial metal hinges thus creating friction induced heat. The heat created by the friction melts the plastic of the frame that sits around the hinge which in turn bonds the hinge of the frame.
At this stage the fronts with hinges are stamped with the logo or name of the manufacturer, the size of the frame, and the name of the style. There are a couple more steps before the temple can be attached to the frame. First, an angular fit must be inserted to force the frame front tilt inward so that it sits squarely on the face. Saws are used to cut the correct angles in the upper edges of the front. While the front is polished, caps are then introduced to fit over the hinges. Keep in mind that at this point the fronts still retain their flat and sharp features. Jumping over to the polishing room, dozens upon dozens of fronts are thrown into a drum full of pumice (stone that is ground into a fine powder) and maple pegs. During the next 24 hours, the mixture of pumice and pegs grind against the fronts. This process smoothes out the rough edges. Sometimes even crushed coconut shells are used during the polishing process.
Finishing The Temples
Eyeglasses and their temples come in various shapes and styles. Depending on the style, the temples undergo a series of operations in which they’re ground and shaped. The next step involves cutting grooves into the ends of the temples. Then the matching halves of the hinges are riveted into the temples. To match the angels of the finished fronts the ends have to be cut. After a series of operations, the temples have reached the final stage of the manufacturing process and are ready to be shipped and sold. They’re packed into envelopes that sort the polished temples by color, style, and size. These envelopes are stored until an optometrist, or an optometric supply house calls them to make an order.
When it comes to manufacturing eyeglasses, attention to detail is essential not only to improve vision but also to provide comfort for the wearer. Also, glasses are considered to be accessories for both professional attire and personal style. Despite the fact that machines implement the manufacturing process, it ultimately falls upon the machine operators to act as quality control agents to ensure that everything is going smoothly.
What happens to the byproduct during the manufacturing process?
Actually, the manufacturing process of eyeglass frames doesn’t produce any byproducts. The only waste created during this process is during blanking, though it’s carefully gathered up and recycled.
The future of frames has essentially been established from the cumulative efforts of the eyeglass industry in the past 50 years. Despite the fact that contact lenses are on the rise and laser surgery is correcting vision problems on an unprecedented scale, eyeglasses aren’t going anywhere. Whether they’re worn as a style accessory or worn for vision problems, people will always desire eyeglasses. As the centuries rolled forward, the introduction of plastic and other light materials have made glasses easier and more enjoyable to wear.