Controlled Substances Act. An Act to amend the Public Health Service Act and other laws to provide increased research into, and prevention of, drug abuse and drug dependence; to provide for treatment and rehabilitation of drug abusers and drug dependent persons; and to strengthen existing law enforcement authority in the field of drug abuse.
What Is Polycarbonate ? The Stuff They Use For The Lenses In Sunglasses, Safety Glasses And Goggles. Polycarbonates are a particular group of thermoplastics. They are easily worked, molded, and thermoformed; as such, these plastics are very widely used in modern manufacturing.
- Using RGP lenses to correct myopia (orthokeratology). - Who should wear rigid gas permeable lenses. - Advantages over eyeglasses. Gas permeable (GP) contact lenses are also known as rigid gas permeables (RGPâs).Although todayâs gas permeable lenses are made of a rigid material that is not flexible, they differ greatly from the original hard lenses of yesteryear.Hard contact lenses made of polymethylmethacrylate (PMMA), were introduced in the 1930âs.rthokeratology is the process of using special gas permeable lenses to temporarily correct/reduce myopia by reshaping the cornea. An eye health professional may refer to this process as corneal reshaping (CR) as corneal refractive therapy or vision shaping.