By ordinary material, I actually mean hydrogel material.Hydrogels are older materials, they've been around since the 1970s, and the idea is that by adding water to the material to make the lens soft, the added water can play a role in making the material breathable.
Silicone hydrogels came out in the '90s, and what's nice about silicon hydrogels is that they have five or six times more oxygen than hydrogels because they have silicon.
At this time, some people will ask, why must emphasize the "oxygen penetration"?
You must have heard the term corneal transplant a lot.A cornea transplant, it's not the same thing as a liver transplant or a kidney transplant, it doesn't require matching, it doesn't require anti-rejection drugs, and the reason is that the cornea doesn't have blood vessels, so anybody's cornea can be transplanted to another person.However, since he doesn't have blood vessels, all of his feeding depends on air going directly into the cornea to achieve a full feeding, and if you wear a contact lens in front of your eye (cornea), it actually blocks that feeding process.
For contact lenses, if you want them to be very healthy and safe to feed, not prone to inflammation, not prone to jealousy, then a silicone hydrogel with high oxygen penetration is better.
