Catalogue Number: 1740
Two boxes of near segment wafers for cement bifocal lenses
Category: Spectacles and lenses
Sub-Category: Spectacle lenses
Year Of Publication/Manufacture: c 1900
Time Period: 1900 to 1939
Place Of Publication/Manufacture: Rochester USA
Publisher/Manufacturer: Bausch and Lomb
Description Of Item: Two small grey cardboard boxes, 67 L x 40 W x 38 H mm, both carrying printed blue logo of Bausch and Lomb on the upper surface and a printed blue identification on the front surface reading: 'BAUSCH & LOMB 10 pairs Cement wafers 32 mm Curve _ Focus _ OPHTHALMIC LENSES'. One box inscribed in ink handwriting 'Peris SEGS and +1.75': the other originally marked in handwriting +2.50, which is crossed out in favour of +1.25 and also marked PERIS. Both boxes contain 30 mm diameter cement wafers each in small envelopes, some with printed identification as being 'AMERICAN OPTICAL COMPANY CEMENT WAFER' with the curve of the lens. Other are in plain envelopes some marked with the dioptric focus. One flat lens in one box with wafer already cemented.
Historical Significance: Benjamin Franklin is generally credited with the invention of bifocals in 1784. These were two separate half lenses fitted together in the spectacle frame. They remained in use for over 100 years. Cemented bifocals were invented in 1884.
Date Acquired: c 1978
Location: Archive office. East wall shelves unit 3. Drawer 4