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.
Eyeglass frames are made out of many different composite materials and formulas, but the basic groupings are metal and plastic. In plastics, zyl is the most common although lower quality plastics are used in the cheaper frames. Nylon is often used in sport sunglasses due to its impact resistance and flexibility.