How Modern Bifocal Reading Glasses Came to Be
The United States man of science, Benjamin Franklin, who persevered both myopia as well as presbyopia, devised bifocals in 1784 to obviate needing to frequently switch between two pairs of eyeglasses.
The original lenses for rectifying astigmia were distributed by the British astronomer George Airy within 1825.
In the history of reading bifocals, the building of eyeglass frames also evolved. Early on glasses were contrived to be either held in place with your hand or by maintaining force on the bridge of the nose. Girolamo Savonarola advised that oculars could be held in place with a ribbon placed over a person’s head, which in turn was fastened by the weight of one’s hat.
Entering modern bifocal history, the contemporary fashion of bifocal eyeglasses supported by temples passing over the ears, was produced in 1727 by the British lens maker Edward Scarlett. These designs were not at once prosperous, however, and assorted styles with attached handles like “scissors-glasses” and lorgnettes stayed fashionable throughout the eighteenth and into the early nineteenth century.
In the early twentieth century, Moritz von Rohr at Zeiss made the Zeiss Punktal spherical point-focus lens system which controlled the eyeglass lens field for many years.
Despite the rising fame of contacts and laser restorative eye surgery, eyeglasses remain rather common, as their engineering has continued to evolve. For example, it’s currently possible to buy frames constituted of special memory metal alloys that return to their correct configuration after being bent. Other frames have spring-loaded hinges.
Glasses have come a long way, haven’t they? In fact, today you can even buy rimless bifocal glasses.
Many of these designs are also distinctly better able to resist the stresses of everyday wear and the occasional accident. Modern frames are likewise ofttimes constructed from robust, light-weight materials such as titanium alloys that were not obtainable in earlier days.
This entry was posted on Thursday, December 31st, 2009 at 4:46 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.