Although the number of hydrogel contact lenses is predominant, it is still not satisfactory in terms of oxygen permeability.From hydrogel to silicon hydrogel, it can be said that a qualitative leap has been achieved.So, what's so good about silicone hydrogels as the best invisible eyes right now?
Silicone hydrogel is a highly hydrophilic organic polymer material with relatively high oxygen permeability.From the perspective of eye health, the key problem to be solved for contact lenses is to improve oxygen permeability.Ordinary hydrogel contact lenses rely on the water contained in the lens as a carrier to transfer oxygen to the cornea, but the water transport capacity is very limited and it is relatively easy to evaporate.However, adding silicon makes a big difference. The organosilicon monomer has a loose structure, a small intermolecular force, and a very high solubility of oxygen in it, which makes the silicon hydrogel's oxygen permeability increase by five times on the basis of ordinary lenses.
The problem that oxygen permeability must depend on water content has been solved, but also brought other advantages.If ordinary lenses increase the water content, with the increase of wearing time, the water will be replenished by tears after evaporation, resulting in dry eyes.However, the silicone hydrogel has a proper water content, and the moisture can be kept stable after wearing, and it is not easy to produce a dry feeling. At the same time, the lenses are soft and comfortable, and the cornea can breathe freely.
Therefore, contact lenses made from silicone hydrogels can always maintain moisture and breathability, improve comfort, and reduce eye damage. These advantages are unmatched by ordinary contact lenses.Although silicon hydrogels can only be used to make short-cycle disposable lenses, they are not suitable for annual and half-year throws, but they are still the best choice among all products.