During the late 18th, and all through the 19th century, spectacles were mostly made with a metal rim extending from around the lense to behind the ear. Before the NHS was invented, a trip to the opticians was quite an expensive thing, and maybe the reason why these glasses are still to be found was that people would pass on there glasses to another member of the family, albeit not the correct perscription it, was better than non at all, if you couldnt afford your own. In wealthy households these spectacles would sometimes be made with gold or silver rims.
 
This is pair of spectacle cases possibly for a middle class family.
 
Dimensions:11cm width