It may truly be said of spectacles that they were never invented but were evolved; the underlying principle of such evolution being enunciated in the axiom ‘Necessity is the mother of invention’ (Jackson 1927). 

The historic evolution of spectacles has been outlined several times, with varying degrees of accuracy and fancy, by authors such as Pansier (1901), Barck (1907), Dunscombe (1911), Von Rohr (1923), Corson (1980), Orr (1985), Rosenthal (1996) and Schiffer (2000). One of the best short and illustrated summaries was written recently, not by a historian but by an optometrist for the benefit of historical re-enactors (Walsh 2001). It is now generally accepted that spectacles were ‘invented’ (more likely improvised) no later than the last quarter of the 13th century by the Italians (rather than the Dutch or even the Chinese) and that their specific area of origin centred possibly on the Veneto region, rather than Pisa or Florence, though each of those cities still has its advocates (eg Ilardi in press). In recent decades the debate has sometimes been driven more by Italian civic pride than by hard evidence, although this has been partly permissible since the corpus of reliable documentary evidence is quite small. If the archaeological evidence were given priority our attention would switch away from Italy altogether, towards the Germanic countries, since only one pair of the earliest rivet-type of spectacles has ever been found in Italy. Walter Gasson demolished many of the arguments concerning the legendary inventors of spectacles, such as Allesandro Spina and Salvino D’Armato, in various articles as long ago as the 1960s. A fair and non-committal summary has recently been written by Ainsworth, concluding that ‘the most likely scenario is of an evolving technology with many people working’ (Ainsworth 2002). Rather than engage in a historiographical survey of differing theories on the earliest origin of spectacle frames, this article argues that certain key principles underlie their subsequent development and that some of what mattered in the 13th century remains not only of concern in the 21st century but, moreover, can inform the work of the modern optometrist and maybe assist in the prediction of future trends.