SZDaily: "It is said that at least 60 percent of the spectacles on the earth are made in Shenzhen... At present, there are nearly 500 spectacles manufacturing companies in the city, mostly in Henggang Subdistrict, Longgang District, producing nearly 200 million pairs of spectacles a year. Ninety-five percent of their products are exported to more than 130 countries and regions, accounting for more than 70 percent of market share in Europe and about 60 percent on the global market."
http://www.szdaily.com/content/2012-07/20/content_6962497.ht...
WarbyParker: "We design our frames here in the US, then source our material (high-quality cellulose acetate) from a 150-year-old, family-owned Italian manufacturer. Our frames are then crafted in China"
http://blog.warbyparker.com/post/12789294212/i-have-a-questi...
As for the Italian manufacturer, it's likely they are referring to Mazzucchelli founded in 1849 and famous for the tortoise shell look. Well, it appears they may have outsourced acetate production to China too!
http://www.optiboard.com/forums/showthread.php/47085-Acetate...
http://www.alibaba.com/countrysearch/CN/mazzucchelli-acetate...