Recent years, almost all contact lenses’ manufacturers have introduced silicone hydrogel contact lens. What is exactly that material has an advantage over the classic material.
First of all, the classic contact lenses uses a material called HEMA, which is a soft, flexible, water-absorbing plastic. The higher water content and thinner of the of the HEMA lens will then lead to more oxygen going through. However, there is a limit on how much water content a piece of plastic can have and obviously a limit on how thin the plastic can be. Silicone hydrogel is a material that don’t have to count on the water content and the thickness of itself
for more oxygen to go through. Silicone hydrogel contact lenses can have 5 times more oxygen go through it compared to the HEMA contact lens.
Popular brands of silicone hydrogel contact lenses include Acuvue Oasys (Johnson & Johnson), Air Optix Aqua (CIBA Vision), Biofinity (CooperVision) and PureVision 2 HD (Bausch + Lomb)
