RARE BIFOCAL or ASTIGMATISM TRIAL SET 

Circa 1900 in original leather covered wood box with celluloid diopter scale and 24 lenses (2 are missing smaller lens). Unusual thin steel surround with small glass lens circle, the purpose of which we do not exactly know, but we have never before seen! 

Dimensions: 5” x 4” x 2” Lens: 1.5”