Nowadays most contact lenses are made of following materials:
- More modern silicone hydrogel, which has a higher oxygen permeability and is a combination of swelling silicone hydrogels, which combine the properties of both soft and hard, in form-stable contact lenses.
There is increasing demand to develop existing materials of contact lenses. In addition to good machinability it is necessary to maintain the quality of the lens mechanical and chemical properties, biological inertness, tolerance, resistance against storage of sediment, easy maintenance and transparency (material should not be influenced by pH of tears, light, hydration and dehydration between each blink, etc.).