The technologies behind your sunglasses

Do you know what your sunglasses’ lenses are made from? It would be easy to assume that they are glass – the clue’s right there in the name, after all! But in fact, while glass is still used in the manufacture of some sun glasses and eyeglasses, today most lenses are made from high-tech plastics which weigh less and break less easily than glass, and that can be treated with filters to protect your eyes from harmful ultraviolet (UV) rays.

The weight of glass lenses – particularly thicker lenses in some prescription eyewear and magnifying readers – can be prohibitive. This can be overcome by using lightweight modern plastics such as polycarbonate, Trivex and so-called “high-index” plastics, which allow thinner, lighter lenses to achieve the same results as a thicker glass lens. Lightweight plastic lenses allow eyeglasses, sunglasses and sunglass readers to be made with lighter, more delicate frames than would be the case with heavy glass lenses. 

Glass lenses can also have the disadvantage of being more prone to scratches and breakage than plastic lenses. Polycarbonate, for example, has a high impact resistance compared to glass, and this means polycarbonate lenses can be great not just for day-to-day use, but also for use in sports sunglasses and eyewear. Trivex is another, relatively new plastic used for corrective lenses. It was originally developed in 2001 for the military as transparent armor, and combines polycarbonate’s shatter-resistant properties and UV resistance, with a slightly lower density and superior optical quality.

One of the most important roles of sun glasses is to provide protection for the wearer against harmful UVA and UVB light. While glass lenses require a UV-resistant coating to provide protection, plastics such as polycarbonate and Trivex have an inbuilt resistance to most UV light without the need for further filters or coating.

At Blue Planet Eyewear we take pride in producing sunglasses and readers with only high-quality materials – and that applies to both the frames and the lenses. Check out our full range of sunglasses, bamboo readers and sunglass readers to find the style that’s right for you.