In their book The History of Modern Cataract Surgery, Marvin L. Kwitko and Charles D. Kelman describe the history of surgical loupes.
The first surgical loupes date back to 1876 and consisted of simple loupes attached to a spectacle frame or a headband. These were made of convex lenses that were decentered to allow convergence and to use the prismatic effects of the periphery. Carl von Hess used such a loupe together with an electrical illumination device attached to a headband.
In 1886, a mechanic named Westien constructed a binocular instrument from two loupes to be used by a zoologist. Von Zehender later attempted to modify these loupes for use in ophthalmology, and the Zehender-Westien double loupe was born. It had a firm base and a lens for lateral focal illumination.
Further development of a binocular magnifying instrument progressed along two pathways: one for diagnostic purposes and one for surgical use, leading to the eventual development of the slit-lamp and the corneal microscope.
By 1912, Von Rohr and Stock had constructed a spectacle loupe that was lighter and less magnifying than Westien’s. It had a working distance of 25 cm and a magnification of 2X. Gullstrand was the first to use these loupes starting the development of a binocular loupe that could be attached to spectacles and bifocals. This model is still used today by ophthalmic surgeons for a variety of surgical procedures. By simply tilting his or her head, the surgeon can view the field either through the spectacle lens or through the loupes. This allows for only using the magnification when needed. However, It a magnification of more than 2X was not practical, due to the fact that the slightest movement of the head would cause large movements of the image in high magnification. Furthermore, optical principles prevented a magnification of more than 2X with these loupes.
For years, the selection of loupes was limited, but loupes from innovators such as Admetec-Vision are lightweight and have stylish frames. Magnification loupes range from entry-level models to loupes with highly sophisticated optical systems. So the choice is yours.
(To read the original chapter online on Google books, please click here)
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