astigmatism

Note: The term astigmatism was introduced by the British astronomer George Biddell Airy (1801-92), who performed a pioneering measurement and description of an astigmatism in his own eye ("On a Peculiar Defect of the Eye and a Mode of Correcting It," Transactions of the Cambridge Philosophical Society, vol. 2 [1827], pp. 267-71). Airy did not use the word in the article, however, and it does not seem to appear under his name until a much later article on the same subject, "On a Change in the State of an Eye affected with a Mal-formation [Read May 25, 1846]," Transactions of the Cambridge Philosophical Society, vol. 8 (1849), pp. 361-62. In the latter article Airy describes "the nature of the effect" as "a geometrical phenomenon, to which the term astigmatism was very happily affixed by the present Master of Trinity College." The "Master of Trinity College," Cambridge, was the clergyman and polymath William Whewell (1794-1866), to whom a number of other scientific neologisms are credited. The word was evidently in oral circulation prior to Airy's use of it in print; in 1831, an unsigned article in The British Critic, Quarterly Theological Review, and Eccesiastical Record (vol. 9, p. 82) mentions astigmatism, "employing a word which we believe Professor Airy is in the habit of using in his lectures on this subject [optics]." For details on Airy and astigmatism, see John R. Levene, "Sir George Biddell Airy, F.R.S. (1801-1892) and the Discovery and Correction of Astigmatism," Notes and Records of the Royal Society of London, Vol. 21, No. 2 (December, 1966), pp. 180-199.