What are contact lenses made of??

According to the type of material, soft Contact lenses They are divided into hydrogel and silicone-hydrogel, Both types are soft hydophilic lenses based on high-molecular materials. What is better to choose? Let's consider each type in more detail.

Since contact lenses are in direct contact with the cornea of the eye, To the materials, underlying them, serious demands are put forward. Soft and elastic, линзы долны практически не ощущаться на глазу, сохранять влагу, Have high biocompatibility and good oxygen permeability, prevent the accumulation of protein deposits, Be resistant to minor damage. And most importantly, Lenses must successfully solve the problem of vision correction – have a high refractive index, Prevent distortion and improve image clarity.

And hydrogel, and silicone-hydrogel perfectly match the above characteristics. However, Each of the materials has its own limitations. So, Hydrogel lenses can have high moisture content, while having limited oxygen permeability. To solve this problem, lenses made of silicone-hydrogel were developed – The addition of a new material made it possible to significantly increase the level of oxygen permeability. However, the lenses have become stiffer, And the material itself – more susceptible to the accumulation of protein and lipid deposits.

On the whole, Silicone-hydrogel lenses can be considered an improved version of their predecessors – hydrogel lenses, And more and more consumers are opting for them. However, even choosing silicone-hydrogel lenses, Do not forget about hygiene – despite the improved material properties, They also need regular cleaning and care.

Источник: realconlens.cn