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.
Hi-Index Lenses. Hi-index lenses are made of a special plastic material that refracts light in a different way than regular plastic lenses. With hi-index lenses, vision can be corrected with less material, making the lens much thinner. Plastics are graded in numbers, such as 1.50 or 1.67. The higher the number, the thinner the lens.