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.
Four years ago I bought a really nice pair of prescription Ray-Ban sunglasses at a local LensCrafters. As one of multiple pairs of sunglasses I wear, the Ray-Bans are still in excellent condition. They're in excellent condition also because they were lost for about two of those four years. LensCrafters advertises that it can make glasses in about an hour and has perpetual sales like the mattress stores.