Beginnings of Astigmatism Understanding and Management in the 19th Century
Within the last 200 years, the perception of astigmatism has evolved from that of an infrequent and peculiar defect of the eye to a distortion almost as common as spherical refractive errors. Most of the significant findings on this condition were made in the 19th century, including the first description by Thomas Young (1773–1829) and the introduction of the treatment methods used today. The purpose of this study was to investigate the milestones in the understanding and management of astigmatism that occurred up to the year 1900. This fascinating history illustrates how knowledge evolves across time, geographical areas, and interdisciplinary boundaries. The first article looking at the use of a cylindrical lens to correct astigmatism was written by George Airy (1801–1892) in 1825. The term “astigmatism” was introduced in by William Whewell (1794–1866) in 1846. Methods for subjective and objective evaluation were subsequently established, including the introduction of a cross cylinder, keratoscope, astigmatic dial, and the development of retinoscopy and ophthalmoscopy. In the last two decades of the 19th century, the first attempt to alter the refraction in astigmatic patients by changing the shape of the cornea was made. It must be noted that diverse challenges were encountered in this field on the way to the development of a treatment, including the technical manufacture of a lens, the precise measurement of the refractive error, and understanding the optical properties of the eye. The importance of the 19th century was that interdisciplinary cooperation, such as that seen in this study, between physicists and astronomers, and mathematicians and physicians, led to the development of comprehensive knowledge on astigmatism.