What are silicone hydrogel contact lenses?
Silicone is a group of flexible, plastic materials that contain silicon, carbon and oxygen amongst other chemicals, while hydrogel is used for contact lenses as it retains a lot of moisture. When contact lenses are made with silicone hydrogel, they have a high oxygen permeability, allowing up to 5 times as much oxygen to reach the eye than traditional hydrogel lenses, while still retaining plenty of moisture.
One reason silicone hydrogel contact lenses work so well is their adaptability. When they're dry, they're firm and hard but when they're introduced to moisture they soften and become flexible, making them fit comfortably and securely.
There's often confusion between what is silicone and ‘silicon'. Silicon is one of the components in silicone, as well as the name of a valley full of rich tech companies, but needs to be combined with other elements to create silicone.