The refractive index of current eyeglass lens materials ranges from 1.498 (CR-39 plastic) to 1.74 (a specific variety of high-index plastic). So for the same prescription power and lens design, a lens made of CR-39 plastic will be the thickest lens available, and a 1.74 high-index plastic lens will be the thinnest.
Principal photography on the film began on April 25, 2016, in Pittsburgh, Pennsylvania, in the Hill District, and wrapped in mid-June 2016. Fences was released in the United States on December 16, 2016, by Paramount Pictures, received positive reviews and grossed $64 million.
Production took place from February to April 2014 in Toronto and Los Angeles. The film had its premiere at 65th Berlin International Film Festival, at Berlinale Special Gala at the Zoo Palast on February 9, 2015. The film is set for a theatrical release in the United States on December 4, 2015.