Some representative refractive indices

SAPPHIRE :  1.762–1.778

HESALITE ( PMMA or Acrylic Glass )  :  1.450–1.492

The first acrylic acid was created in 1843.

Leading World Suppliers of Engineering & High Performance Plastics : DuPont, BASF, Ticona, Mitsubishi, Cham Chung.

Worldwide manufacturer of PMMA products with a different properties sold under the – Perspex, Crylux, Plexiglas, Acrylite, Hesalite, Lucite, Cyrolite, Simplex and Oroglass. The ACRYLITE®  trademark in the Americas and under the PLEXIGLAS®  trademark on the European, Asian, African and Australian continents.

The glass of STRELA  Cosmoswatch  was made from Hesalite with special high gloss properties.

Airplane pilots whose eyes were damaged by flying shards of PMMA fared much better than those injured by standard glass, demonstrating better compatibility between human tissue and PMMA than glass.

Modern designers, especially in the 1960’s and 1970’s, seeking to give their products a space age aesthetic, incorporated Lucite and other PMMA products into their designs, especially office chairs.

Modern sample of Acrylic – ” Perspex ” is a LEXUS Car

Some surfaces exhibit retroreflection. The structure of these surfaces is such that light is returned in the direction from which it came. When flying over clouds illuminated by sunlight the region seen around the aircraft’s shadow will appear brighter, and a similar effect may be seen from dew on grass. This partial retro-reflection is created by the refractive properties of the curved droplet’s surface and reflective properties at the backside of the droplet.