Final answer:
The statement pertains to polycarbonate, a material known for its excellent optical clarity, lightness, and impact resistance, often used in eyewear and protective gear. Its chemistry involves a reaction between BPA and phosgene COCl2.
Step-by-step explanation:
The statement "Great balance of optical clarity, thinness & impact-resistance" is typically associated with polycarbonate. Polycarbonate materials boast excellent properties that make them ideal for use in various applications that require durability along with optical precision. These materials are known for their high impact resistance, which is significantly superior to glass and other plastic materials. This trait, coupled with their inherent lightweight nature, makes them an excellent choice for eyewear, safety glasses, and shields.
One of the main raw materials in producing polycarbonate is bisphenol A (BPA), which reacts with phosgene COCl2. Additionally, polycarbonates are well suited for applications where both high clarity and safety are mandated, such as in eyeglass lenses. They can also be further enhanced with coatings and treatments, such as those for polarization or photochromic properties to protect against UV light and glare.
These additional treatments can imbue polycarbonates with a variety of special optical effects, like adjustment to varying light conditions seen in photochromic lenses. Conversely, materials such as glass, while offering optical clarity, are heavier and more brittle, making them less ideal where impact resistance and weight are crucial considerations.