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.
Can you believe it's already been five years since Bella Swan and Edward Cullen's epic romance first filled theaters? The first  Twilight  film came out November 5, 2008, and like summer flowers, a followup came every year after. Until this year. Sigh. We know the end of the saga has left a huge gap, so if you need more Twilight in your life â the way Edward and Jacob need Bella â you're in luck!