The basic material for the production of soft contact lenses is HEMA. This methacrylate allows increasing the water content and therefore contact lenses permeability for oxygen from the original 40% to about 80%.
Currently, there is a new generation of soft contact lenses, which uses silicone hydrogel. This material is used for producing contact lenses for continuous wear just because of the high oxygen permeability. The disadvantage of soft contact lenses is the predisposition to produce deposits.
Modern soft contact lenses were invented by a group of Czech chemists over the leadership of the scientist Otto Wichterle.