HOW SPECTACLE FRAMES ARE MADE
History and Background to the Development of Spectacle Frames
The ancient Greeks made the first studies of vision and the workings of the eye. They also attempted to understand magnification and to use it to understand vision problems. Alhazen, an Arabian scientist who lived during the eleventh century, studied the refraction (bending) of light and the connection between optic nerves and the brain. It was the thirteenth century Polish scientist, Vitello, who first understood that the shapes of lenses could be used to control the focus of light rays.
In 1257, the English friar Roger Bacon explored so many aspects of science that he was imprisoned by the monks of his Franciscan order who were suspicious of his knowledge. While he was in prison, Friar Bacon sent Pope Clement IV some magnifying lenses for reading; despite Bacon's controversial standing, the monks who laboured over detailed manuscripts and copy work quickly adopted the use of his spectacles. Bacon's work occurred at the same time as that of Salvino d'Armato of Florence, Italy, and several Chinese and German scientists. All can be thanked for their collective invention of spectacles.
The invention of devices to keep spectacles on the nose took several more centuries. The earliest eyeglasses were unframed lenses that were simply held by hand in front of the face. Alternatively, two lenses were mounted in a half frame that could be held with one hand. Spectacles also were attached to hats or tied around the head with bands made of leather or ribbon. Will Somers, a jester to the court of Henry VIII, sported a suit of armor with spectacles attached to the metal helmet with rivets. The painter El Greco portrayed Cardinal Niño de Guevara wearing glasses with cords that looped over his ears. The seventeenth century design called the forehead frame consisted of a metal band that encircled the head and had metal frames mounted to it.
The most common frames held two lenses on a frame that rode on the lower part of the nose. Lightweight materials were used to lessen the burden and pinching of these "nose frames." In the court of the Spanish King Philip V and Queen Marie-Louise (about 1701), all 500 of the queen's ladies-in-waiting wore tortoise-shell frames because of their light weight. This style saluted both fashion and superstition; the frames supposedly brought good luck because the tortoise is sacred in China. Attempts at stylistic designs were varied and clever. The bridge pieces that rest on the nose were decorated in endless ways. Lenses were mount-ed in fans, watch fobs, and on walking sticks. The status-conscious had their nose frames made of gold or other precious materials or employed artists to decorate the frames with coats of arms.
Other than nose glasses, lens wearers could choose the monocle (a single lens in a frame or holder), the lorgnette (a pair of lenses with a nose bridge and a single handle on one side), a quizzer or quizzing glass (a monocle that was mirrored so the wearer could see to the rear as well), the perspective glass (a single lens worn on a ribbon and used for distance vision), or scissors glasses that had two eyepieces mounted on a hinged handle that was held up in front of the nose. Finally, in 1728, Edward Scarlett of London developed temples for frames. These clamps gripped the temple area and held nose glasses more securely to the face. A loop at the end of each temple piece held ribbons that were tied around the head or wig. By the 1880s, temples were curved to extend and fit over the ears to hold spectacles in place.
In the Colonies, spectacles were imported and were very expensive until American glass-making skills improved enough to develop an eyeglass trade. Just as curved and fitted temples were developed and adopted all over the world, fashion reverted to a style called the oxford that consisted of nose glasses improved by a more elastic and wearable bridge. These glasses were also called pince-nez and had nose pads fitted to small springs on the flexible bridge. Presidents Teddy Roosevelt and Calvin Coolidge wore oxfords. During the 1900s, simple steel-framed glasses were the most common, although less expensive frames were available in a material called gutta-percha—a rubbery plastic-like substance. Tortoiseshell and horn-rimmed glasses became popular in the 1920s and 1930s, but many of these frames were actually made of celluloid, an early plastic that could be dyed and moulded to resemble animal horn or tortoise shell. Steel-framed spectacles and sunglasses were issued to millions of servicemen during World War II.
The business of manufacturing eyeglass frames and lenses made its most dramatic leap in the twentieth century with the rise of plastics. Plastic lenses are lighter in weight and can be manufactured as bifocals, trifocals, and quadrifocals to correct a wider range of vision problems. Frames made of plastic are also less expensive. A broad range of styles and colours can be made in plastic and changed to suit wardrobes, fads, and moods. Sunglasses also became affordable, thanks to the plastics industry, but Hollywood was responsible for their popularity. Large, square-rimmed glasses like those worn by Clark Kent became popular among men in the 1950s, and the ladies favored "cat's-eye" glasses that angled up at the temples. Granny glasses with fine metal frames accompanied the flash of the "flower power" generation in the 1960s and may have been responsible for making antique eyeglasses popular collectibles. Although contact lenses were also developed during this century and have become very popular, the variety of available eyeglass frames has kept glasses fashionable.
Eyeglasses frames are typically made of either metal or a type of plastic called cellulose-acetate. Cellulose acetate is derived from cotton and is flexible and strong. It is produced in long narrow sheets that are slightly wider than eyeglass frames. The sheets are up to 3 ft (0.91 m) long and 0.33 in (0.84 cm) thick.
Eyeglasses manufacturers may retain their own staff of designers or use outside consultants to design frames. The consultants often include fashion designers, who create their own lines of eye wear that change along with trends in clothing design. The designers' names are important in selling eyeglasses and especially in interesting fashion-conscious buyers in multiple pairs of glasses or sunglasses. There are definitely trends or fashions in eyewear including light- or dark-coloured frames, thick or delicate ones, and decorative shapes or ornament-bearing styles. Specialized frames for children and half-frames for reading glasses are also designed with an eye to style.
Designs also incorporate certain standards including bridge size and eye size. The bridge size allows for different thicknesses of the upper part of the nose where the nose pads on the glass's rest. Three eye sizes are standard for the range of dimensions of corrective lenses. Each style is typically manufactured in four different colours, so a single style will result in 12 combinations of colour and dimension. Frame designers and manufacturers typically produce a new style every few months and discontinue styles if they don't sell well.