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,
Quartier des spectacles 30 performance halls totalling almost 28,000 seats ( including the Place des Arts cultural complex), international festivals, art galleries and various cultural exhibition and broadcast facilities. The Quartier des spectacles hosts nearly 8,500 jobs linked to cultural activities, from education and creation to production, exhibition and broadcasting. The area is now home to many of Montreal's major festivals, including the Montreal International Jazz Festival, the Francofolies and the Just for Laughs comedy fest. Urban design features of the district include concert spaces, tiered green space and stonework, illuminated fountains, various forms of street lighting, mist machines, bike paths and illuminated