Figure 1: C1950s frame showing Day & Cartwrights variation and a 21st century modification to a Norville Optical Gloster library frame
A casual glance at modern dispensing trends might cause one to believe the only spectacle solutions for presbyopia were either single vision lenses or the increasingly ubiquitous varifocal that was patented in 1907 by Owen Aves, although it was not successfully developed commercially until the 1960s.
In 1784, Benjamin Franklin referred in a letter to ‘double spectacles’ consisting of two individual lenses of differing powers place in each eye rim, and so with some contention, he is regarded by many as the inventor of the style now known as the Franklin Split bifocal. Subsequent developments led to the cement bifocal in 1888, and later the fused and solid one-piece bifocals.
This article reviews some of the historical alternatives that may still have a place in our dispensing armoury today. The first patent to be granted for spectacles was Addison Smith’s design for a frame with a supplementary front hinged at the top. The lenses required for reading were usually glazed to the base frame and concave lenses of equal power to the reading addition glazed to the hinged frame.
When the hinged frame is down the spectacles are suitable for distance vision and when raised, it is suitable for reading. The patent was granted in 1783, with later variations having a knob for turning the additional lens front (Day & Cartwright in 1886), a spring mechanism (Lazarus Threlfall Baines in 1889) and even a half-eye supplementary front (AH Strassburger in 1902) (figure 1 - see top of page).
John Richardson’s patent of 1797 had the supplementary lenses hinged at the side and were originally intended to hold either the reading addition or a plano tint. There were many options when glazing Four Lens spectacles, as they are now known (figure 2), including:
- Reading power in frame front, minus supplementary lenses of power equivalent to the reading addition swung to the front when distance vision is required.
- Distance power in frame front, plus powered supplementary lenses to convert to reading use.
- Unpowered, sometimes tinted, in frame front, with reading power in supplementary lenses.
Figure 2: Shell and silver four lens frames from 1800-1840
The Double D style was extremely popular because of the protection offered from cinders and soot when travelling by rail and hence are often described as Railway Spectacles. Dr Herbert D Everington patented a variation in 1930 that he named Duo-Focal spectacles, claiming they were no more expensive and often cheaper than bifocal spectacles, and the reading addition could easily and cheaply be increased as presbyopia advances. They were manufactured by the well-known firm of Curry & Paxton (figure 3).
Figure 3: 1930s Duo-focal spectacles
Drop and grab fronts, popular in the early 1900s, proved a simple and inexpensive solution (figure 4), the former having lugs intended to rest on the frame sides behind the frame front while the latter fitted in front by a variety of methods. In more recent times, half-eye versions have been produced from standard clip-on sunglass mounts.
Figure 4: 1920s drop, grab and slip-on fronts
Modern frames came in all shapes and sizes, perhaps the inverted half-eye would not draw unwanted attention – ideal for myopic patients who read comfortably without a correction. Sometimes called Pulpit Glasses, the blued steel frame was made by Carpenter & Westley of Regents Street, London in the 1860s.
The style lends itself well to many present-day rimless frames, nylon supras and polymils, while the ‘half-eye full frame’ may easily be made by retro fitting stops to a standard frame (figure 5).
Figure 5: 1920s rimless and 1860s blued steel pulpit frames
Figure 5B 1950s acetate
Figure 5C: 1980s Birch Royal Albion with half eye stops
Perhaps not so easy either to source or glaze but for the presbyope with good distance vision not requiring a large field of view, perhaps consider a much smaller lens such as the single wire frame glazed R&L +2.00D (16mm diameter) or the 1920s pince-nez, with its bespoke sterling silver case, glazed R&L +1.50D (16mm width) (figure 6 pictured next to a full-sized frame).
Figure 6A: Single wire frame
Figure 6B: 1920s pince-nez
- John Dixon Salt is current chairman of the Ophthalmic Antiques International Collectors’ Club (OAICC).
