In the Eye of the Beholder: Sight, Illusion, and Disorder
Refractive Errors
24. Trial lenses and frames,
circa 1890, from the collection
of Thomas A. Farrell, MD |
Approximately half of the people in the United States depend on eyeglasses or contact lenses to see clearly. The most common refractive errors are explained in the exhibit, where visitors may "read" eye charts to test their vision, and look through lenses of varying powers to see the effects they produce. Also on display is an eye doctor's trial lens case from about 1900; it includes dozens of convex, concave and cylindrical lenses in a wide range of powers. These were used to test for hyperopia, myopia and astigmatism, respectively. Modern refractive equipment incorporates all these lenses into one unit. |
| Contact lenses are normally employed to correct vision problems, but they are also used as prostheses to cover scarred or injured eyes. Clear contact lenses are displayed alongside prosthetic lenses painted to match companion eyes. The exhibit also includes early contact lenses that covered the sclera, a tinted lens, and a fashion lens adorned with the image of Mickey Mouse. |
25. Scleral contact lenses, circa 1948, from the collection of Thomas A. Farrell, MD |
26. Wellsworth DeZeng phoroptor and auxiliary lenses, circa 1925. |
27. Lens production, circa 1894, from Catalogue and Price List of Optical Instruments, Philadelphia: Bonschur & Holmes, 1894, pp. 27, 77. |
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