How to identify silicone hydrogel contact lenses?

Silicon hydrogel is a new contact lens material frequently mentioned in recent years, and the advantages of silicon hydrogel are obvious compared with the past hydrogel material. However, the silicon hydrogel claimed by many businesses in the publicity is actually only a small amount of silicon components, and can not be called a real silicon hydrogel contact lens. Today, we will teach you how to distinguish between real and fake silicone hydrogel materials.


 The most fundamental and direct way to distinguish between true and false silicone hydrogels is to look at the oxygen permeability of the product, that is, the value of DK/t. According to relevant national regulations, this data needs to be marked on the product specification and registration certificate, so the way for consumers to check is very simple. The oxygen permeability coefficient of hydrogel and silicon hydrogel is very different, the oxygen permeability is higher than 80 can be identified as silicon hydrogel contact lenses, the oxygen permeability of good material can even reach about 100, while the oxygen permeability of hydrogel is only about 20, because the oxygen permeability of its material is mainly dependent on the water content to achieve, and because the water content of most contact lenses is between 40%-60%. Therefore, it is difficult to achieve particularly high oxygen permeability under the premise of material limitations.


In addition, the material of silicon hydrogel is temporarily not suitable for long-period contact lenses, generally speaking, the day throw, the month throw can be made of silicon hydrogel, and the year throw, half a year throw is often not made of silicon hydrogel, we must polish our eyes oh! Recently, many businesses have begun to hype non-ionic materials, claiming that non-ionic materials are also new materials with strong oxygen permeability, but non-ionic materials are actually still ordinary hydrogel materials, and the oxygen permeability coefficient naturally cannot be compared with silicon hydrogels.