History: Not only, but also

^{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.