What are the types of contact lenses?
Contact lenses from the production of materials, use cycle, water content, center thickness, etc., there are a variety of different categories, because the lens parameters are too much, the classification is more detailed in order to facilitate the wearer to choose on demand. Today, we will introduce the types of contact lenses from the three most common categories: material, life cycle, and water content.
Depending on the material from which they are made, contact lenses can be hard or soft. The texture of hard contact lenses is hard, not easy to deform, and the purpose of correction is achieved by changing the shape of the cornea, also known as night wear lenses, which can be worn when sleeping. The texture of soft contact lenses is very soft, because the shape is easy to change, the water content is much, so it is more comfortable to just wear, and it does not need a long adaptation time. Soft contact lenses are divided into hydrogel and silicon hydrogel according to the material, from the name can be seen, both materials belong to organic polymer substances, but silicon hydrogel belongs to the upgraded version of hydrogel, oxygen permeability is dozens of times that of hydrogel.
According to the use cycle, contact lenses can be divided into two types: long cycle and short cycle. The traditional lens use cycle is relatively long, such as annual throwing, half-year throwing, etc., and the short cycle includes day throwing, month throwing, and so on. The shorter the use cycle, the less protein precipitation may accumulate, so the healthier it is. If there are conditions, author also recommends choosing short-period contact lenses. Daily disposable contact lenses, also known as disposable contact lenses, are thrown after wearing, and are currently the safest and healthiest type of contact lenses.
According to the water content, 30%-50% is low water content contact lenses, 50%-60% is medium water content, and more than 60% is high water content. The higher the water content of the contact lens, the higher the hydration of the lens, and the more comfortable it will be from the point of view of wearing the feeling, but its disadvantage is that the water evaporation rate becomes faster, which is easy to cause dry eyes, so it is not suitable for people with dry eyes.