Acrylic is a transparent thermoplastic homo-polymer known more commonly by the trade name “Plexiglas.” The material is similar to poly-carbonate in that it is suitable for use as an impact resistant alternative to glass. It is generally considered one of the clearest plastics on the market. Some of the first applications were in WWII when it was used for submarine periscopes as well as airplane windows, turrets, and canopies. Airmen whose eyes were injured due to shards of broken acrylic fared much better than those affected by shards of shattered glass.
Acrylic in the modern era and in general is used for a variety of applications that typically take advantage of its natural transparency and the impact resistance of certain variants. Common uses include lenses, acrylic nails, paint, security barriers, medical devices, LCD screens, and furniture. Because of its clarity, it is also often used for windows, tanks, and enclosures around exhibits.