Currents may also be generated by density differences in water masses caused by temperature and salinity variations. These currents move water masses through the deep oceanâtaking nutrients, oxygen, and heat with them. Occasional events also trigger serious currents. Huge storms move water masses.
Ray-ban and most other manufacturers frames are made from Plastic compounds. Ray-ban used to make all its glasses out of 'glass'. Now it makes its sunglass products out of scratch resistent plastics. Often they will 'feel' like glass but are in fact most usually plastic production.
I agree with both Jon and Stephanie. That is, Ray Ban makes high quality sunglasses that have great design (Ray Bans are a classic, timeless design) and are in high demand. And, Luxottica has a monopoly on sunglasses worldwide. They control 80% of the market. They own sunglass brands, they produce for other brands, and they own retail distribution.