Contact lenses can be divided into hard contact lenses and soft contact lenses according to the material, so what are the similarities and differences between these two types of contact lenses?
The materials of rigid contact lenses are mainly polymers such as silicon fluoride, which have good oxygen permeability, are not easily deformed, and have a long lens life. But in terms of wearing experience, it is not as comfortable as soft mirrors, so it takes a long time to get used to it. Hard lenses are usually worn at night and taken off in the morning to change the curvature of the cornea so that the corrective effect is maintained.
Soft contact lens materials are mainly divided into two categories: hydrogel and silicone hydrogel. Both hydrogel and silicone hydrogel are organic polymers with strong hydrophilicity, which are soft and easy to deform, and are more comfortable to wear. However, the oxygen permeability of hydrogel lenses is limited by their water content, so it is necessary to control the wearing time to avoid corneal hypoxia. The silicone hydrogel lens is developed by adding silicon molecules on the basis of hydrogel, so it has a breakthrough improvement in oxygen permeability. The biggest disadvantage of silicone hydrogel may be that the lens is slightly harder and the foreign body sensation is more obvious, which leads to a corresponding increase in the time required for the eyes to adapt.
The material of the contact lens is very important, it can directly determine the oxygen permeability of the lens. Generally speaking, the higher the marked DK value, the stronger the ability of the lens to transmit oxygen. Therefore, when wearing contact lenses for a long time, it is necessary to choose lenses with high oxygen permeability as much as possible.
Another thing to note is that no matter what kind of contact lenses you wear, you must pay attention to cleaning and maintenance, so as to avoid affecting the service life of the lenses and the health of your eyes.