Highly renowned firm founded in Jena in 1846 by the German industrialist Carl Zeiss (1816-88), specialized in the manufacture of microscopes, laboratory optical instruments, and astronomical instruments. With the help of the German optician Ernst Abbe (1840-1905) from 1866 onward, Zeiss introduced many significant improvements in its instruments and, starting in 1872, produced excellent objectives that were the fruit of painstaking mathematical analysis. Abbe invented many original instruments and established the basic theory of image formation in microscopes. He eventually acquired the firm and set up a foundation (still in existence) to help its workers and the entire community of Jena. The company remained one of the most important and innovative of the 20th C., but after World War II much of the workshop machinery and many of its technicians were transferred to the USSR. Zeiss was split up into two separate entities, one in West Germany, the other in East Germany. After German reunification, the two entities re-merged. A museum in Jena now chronicles the history of the Zeiss business.