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.
Finished in 2005, only months before the playwright's tragic death at the age of 60, the cycle stands as one of the foremost achievements in the American theater. The original Broadway production of Fences opened in 1987. It earned 4 Tony Awards that year, including Best Play and Best Actor for James Earl Jones (in the role now being tackled by Mr. Washington).