Soft contact lens is made of ?
Ans. is 'b' i.e., HEMA Types of contact lenses Depending upon the nature of the material used in their manufacturing, the contact lenses can be divided into three types : - i) Hard lenses : - Made of polymethylmethacrylate (PMMA). ii) Rigid gas permeable (RGP) lenses : - Copolymer of PMMA, silicon containing vinyl monomer and cellulose acetate butyrate (CAB) are used to manufacture RGP lenses. iii) Soft lenses : - These are made up of hydroxymethymethacrylate (HEMA).
PMMA
HEMA
Cellulose acetate butyrate
Vinyl monomer