REVIEW OF THE LITERATURE

Glass workers' cataract Frequent occurrence of cataract in glass blowers and blacksmiths has been merltioned in text books of ophthalmology way back i n the 18th century (Wenzel 1786; Beer 1819, A r l t 1858, Knies 1892). The f irst examination of a large group of glass workers was published by Meyhofer in 1886. He examined 506 glass workers and found that 27% of those over 40 years of age had cataract. Legge (1907) examined 513 glass workers and 278 controls. He found that 56% of glass workers and 17% of controls over 50 years of age had cataract. A Russian investigation including 1359 workers (Kaplan 1936) reported cataract in 26.6% of glass workers and in 10.4% of controls over 40 years of age. A large number o f additional studies of glass workers have been published, but none of them included controls (Hirschberg 1898, Probsting 1899, Robinson 1903 and 1907, Stein 1913, Huber 1914, Wick 1922, Cords 1926, Best 1927, Schlapfer 1930, Fatorel l i 1953, Barthelmess & Borneff 1959). It is di f f icul t t o evaluate these studies as different authors seem to have different definitions of cataract as well as different methods of examination. These differences are reflected in a considerable variation of the frequency figures. Most of the earlier studies include examinations made with just an ophthalmoscope often with undilated pupils. However, Wick (1922) and some of the later investigators used a slit lamp microscope. There are some authors who do not believe that glass workers suffer from cataract more often than other workers. Snell (1907) made inquiries i n 15 glass works and examined 100 glass workers, but he could not find any case of cataract. Dunn (1950) conducted a-survey of medical and compensation records from 1921-1950 and reported no cases of cataract in glass workers.