Optician more important and dignified. Far-sighted or aging colonial Americans imported spectacles from Europe. Spectacles were primarily for the affluent and literate colonists, who required a valuable and precious appliance. Benjamin Franklin in the 1780s developed the bifocal. Bifocal lenses advanced little in the first half of the 19th century. The terms bifocal and trifocal were introduced in London by John Isaac Hawkins, whose trifocals were patented in 1827. In 1884 B. M. Hanna was granted patents on two forms of bifocals which become commercially standardized as the "cemented" and "perfection" bifocals. Both had the serious faults of ugly appearance, fragility,
Earth's Greatest Spectacles first episode - New England, is aired at TPT 2 on 4 November 2017. Earth's Greatest Spectacles Earth's Greatest Spectacles (released in some countries as Seasonal Wonderlands) is a 2016 British nature documentary series created and produced by the BBC, first shown in February 2016 at BBC Two and BBC Two HD. The series takes on stunning seasonal changes based on the three locations where it reveals the dramatic process which occur for each year and showing how wildlife adapts to cope with the changes. The series was composed by David Mitcham and narrated by Domhnall Gleeson. Earth's Greatest Spectacles