The 19th century was a fertile time for the creation of new antique eyeglasses styles in America, as well as innumerable variants on existing configurations; pince nez were first made in this era, and Windsor glasses, which survive in use to this day, also put in their first appearance in the 1800s.
This period was probably so rich in ophthalmic history because manufacturing technology had made immense leaps forward, but the “best” solution to the making eyeglasses had not yet been found, leading to diverse, interesting experiments in the field of applied optics that lead to the vintage eyeglasses treasures collectors enjoy today.
Windsor glasses are defined by a number of distinctive features. Though these features are found in other antique glasses of the period (as well as earlier and later eras), there are no others which possess all of these features, which permit you to identify Windsor antique eyeglasses quickly and definitely:
Round lenses and eyerims.
A “nose saddle” bridge which is a very simple bridge type, consisting of a gently arched piece of metal between the eyerims. The presence of separate nose pads, plaquettes, or other retaining devices means that the spectacles in question are not Windsor glasses.
Frequent use of celluloid as a coating for the frames or even the lenses (to achieve a sunglasses effect), though this is not an inevitable feature and thus is not primarily diagnostic of whether or not specific spectacles are Windsors. However, the presence of celluloid, as well as other coatings such as plastic later in the history of these glasses, does not disqualify them from being considered Windsors, either.
Riding bow temples – these are thin wire temples with a strongly curved further extremity, so that they can be hooked over the ears. They were an early 19th century British invention which quickly spread abroad, and were originally meant to keep spectacles in place while galloping about on horseback, a rapid, jolting motion that might dislodge other eyewear. In the case of Windsor glasses, riding bow temples were adopted simply to keep the glasses in place, since they exert absolutely no gripping action on the nose and would slip off immediatley if not for the wires hooked firmly behind the ears.
Generally, though not always, slender metal construction of eyerims, bridges, and temples, though these may look thicker thanks to heavy rubber or zylonite coatings.
Antique Windsor glasses were produced with frames made from practically every metal then used in the eyeglass industry – including Roman steel (a soft variety), hard steel (popular in the Civil War period), gold-filled, silver, solid gold in various karats of purity (up to a maximum of 14 karat gold), aluminum, brass, nickel, and a host of alloys as well.
Though it was not until around 1880 that Windsor vintage glasses rocketed to success in the United States and became fully as popular as other types of vintage eyewear – with such eminent personalities as Theodore Roosevelt wearing them alongside pince nez – there are existing examples, apparently of American manufacture, dating back as far as the early 1840s.