It is Sulphonation of Copper. It is generally available in 5H2O (Crystal) form, though anhydrous is also available. Copper sulphate, blue stone, blue vitriol are all common names for pentahydrated cupric sulphate, which is the best known and the most widely used of the copper salts.t is Sulphonation of Copper. It is generally available in 5H2O (Crystal) form, though anhydrous is also available. Copper sulphate, blue stone, blue vitriol are all common names for pentahydrated cupric sulphate, which is the best known and the most widely used of the copper salts.
Disposable soft lenses. Contact lenses were first recognized in 1945 by the American Optometric Association. Over 38 million people wear contacts in the United States alone with international numbers topping 125 million. As more and more people receive proper eye care, the use of contact lenses continues to grow.
Advantages over glasses. 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. Considered innovative and technologically advanced for the time, these hard lenses were nearly rendered obsolete by soft lenses that debuted in the early 70âs. A decade later, rigid gas permeable lenses appeared on the scene.