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.
What is the difference between cellulose acetate frames and injection molded plastic frames? Cellulose acetate is hypoallergenic, made from a renewable resource, lightweight, and very strong. It is made from cutting, forming and polishing sheets of plastic. Cellulose acetate is the highest quality plastic material for eyeglasses. As the name implies, injection mold frames are made by injecting a more brittle petroleum based plastic that is liquified, then injected into an aluminum or stainless steel mold.