Rigid and soft corneal contact lenses which is better

Soft corneal contact lenses: hydrogel is the basic material. This material is hydrophilic and soft, with good oxygen permeability and compliance, comfortable to wear, wide field of vision and natural appearance, which has been gradually accepted by refractive error sufferers. However, soft contact lenses are still characterized by strong surface polarity, which is easy to adsorb polar substances in the environment as well as precipitates, disease-causing microorganisms and components of care solution in the tear fluid, and are susceptible to the influence of temperature, humidity, and acid/alkali environmental factors, which makes their durability poorer, and the maintenance and care of them more complicated, and make them prone to breakage. They are less durable and more complicated to maintain and care for, and the lenses are prone to breakage.　　The difference between rigid corneal contact lenses and soft contact lenses lies in their obvious advantages and disadvantages in addition to the concept; advantages and disadvantages of rigid corneal contact lenses: Advantages of rigid contact lenses RGP lenses 1, good physiological solubility, so that long-term wear of RGP lenses is not easy to cause corneal hypertrophy and edema. 2, high oxygen permeability, not easy to cause corneal hypertrophy and edema.　　2, high oxygen permeability, not easy to cause hypoxia and dry eye, will not cause changes in the number of corneal endothelial cells.　　3, to prevent myopia or astigmatism deepening, vision correction effect is better than soft contact lenses.　　4、Simple maintenance, long service life; under proper care, the lenses can be used for up to 2-3 years.　　5, Long-term use of lenses is cheap.　　6, long-term use can maintain the physiological health of the cornea, high security.　　7, Because of wearing soft contact lenses and long-term lack of oxygen, eye congestion or lead to neovascularization, dry eyes, poor vision correction, the eyes can be changed to RGP lenses after restoring health.　　According to domestic and international data, RGP lenses can effectively control the growth of myopia in teenagers.　　Disadvantages: It takes about a week to get used to the strong "discomfort" when wearing it for the first time. Also, the unit price is high, so it's not easy to get them from an ordinary optician.　　Advantages and disadvantages of soft contact lenses: (a) Advantages of soft contact lenses 1, the material is a kind of hydrophilic synthetic polymer compounds, according to the amount of water content is divided into low water content (30%), medium water content (30% ~ 60%), high water content (60%). High water content makes the lenses soft, elastic, with good oxygen permeability and no obvious foreign body sensation when used initially.　　2. Comfortable wearing is the most important feature. The lens is large (12.5-14.5mm), fully covering the cornea, so that dust and foreign matter are not easy to enter the eye, and not easy to shift and fall off, which is very suitable for wearing when participating in sports activities.　　The edge of the lens is tightly attached to the edge of the corneal sclera, so it is not easy to be noticed, so it has a beautiful appearance. It can be dyed or painted for eye beauty and orthopedics.　　4、It has good plasticity, very comfortable to wear and short adaptation time. Since there is no need for repeated adaptation, it can be worn intermittently. Large diameter, the edge of the lens is located under the upper eyelid, avoiding the foreign body sensation caused by the friction between the eyelid and the edge of the lens, and the lens will not fall out of the eye. Because of its softness, water absorption, and large diameter, it can be used as a therapeutic treatment for ocular surface disorders.　　Disadvantages: 1. Low material strength, easy to break. The lens is malleable and less effective in correcting corneal astigmatism.　　2, strong surface polarity, easy to adsorb sediments in the tear fluid, pathogenic microorganisms and components of the care solution, leading to ocular complications, so the cleaning and disinfection procedures require strict, and must consider the compatibility of the lens and care products.　　3, Because it is a soft material containing water, it is easy to be contaminated or moldy, so it must be strictly disinfected.