Kryptok, the Better Bifocal, Circa 1900
By Andrew Karp
Monday, February 12, 2018 12:29 AM
Joseph L. Bruneni’s “Looking Back, An Illustrated History of the American Ophthalmic Industry,” is an invaluable source of optical history. Among the events chronicled in Bruneni’s book is the development of multifocals, including the invention of the Kryptok, a new type of bifocal that was introduced 120 years ago.
As Bruneni explained, “Grinding the segment of a bifocal lens involved a delicate procedure. One side of the segment was matched to the curve of the depression and the opposite curve selected to match the front curve of the distance lens. The glass segment was then cemented into the concave depression. The cemented segment was exposed and this was the chief drawback of the lens.
“Segments were easily dislodged, dirt accumulated in the junction and their visual performance was poor. This suggested a need for improvement by John Borsch. His answer was the three-part Kryptok lens. In this new form, a carrier lens would be cemented over the entire front surface, covering both the distance and near portions of the lens. This three-piece improved bifocal was covered by a new patent issued to Borsch in 1899.” Kryptok lenses quickly became popular with eyeglass wearers, who preferred them over the ugly split and cement bifocals that had been their only alternative. The Columbian Optical company purchased the marketing rights for four states from the Kryptok Company. Columbian made sure local eyeglass wearers knew where to order “invisible” bifocals, as advertised. The accompanying photo shows how their store at 624 15th Street in Denver looked in 1904.
Source: “Looking Back, An Illustrated History of the American Ophthalmic Industry” by Joseph L. Bruneni. VISIONMONDAY.COM FEBRUARY 2018 @VisionMonday Facebook.com/VisionMonday 37