First made in 1887, they went bifocal in 1958
... 1958 ---- The plastic material HEMA was discovered [DOC] [TLE] Discoveries and Inventions [PAR] Aug 19, 2013 ... 1958 - Van Allen (radiation) belt; 1961 - Yuri Gagarin is the first person to orbit .... 
1885 - transformer; 1886 - Internal Combustion Engine; 1887 - gas mantle ... 
1760 - bifocal lens - Benjamin Franklin; 1796 - smallpox vaccine - Jenner .... 
William Shockley and Walter Brattain - 1956 NASA created - 1958 Birth... [DOC] [TLE] Miscellaneous 5 - Quotes - Tripod [PAR] It's better to belong to the first group because there is less competition.