How to choose contact lenses

How to choose contact lenses

The emergence of contact lenses has made many friends who pay attention to their appearance take off their glasses and wear contact lenses, which can not only correct vision and increase the effect of the eyes, but also provide great convenience in life. Whether it is for convenience or aesthetics, many myopic people choose to wear contact lenses, but some people buy contact lenses very casually and do not pay attention to them when using them, which results in hurting their eyes and even causing permanent damage to their vision. In fact, contact lenses are medical devices rather than ordinary goods, so you must go to a regular optical store or glasses online mall to buy them. Be sure to pay attention to the following aspects when wearing: The curvature and diameter of the lens vary from person to person According to experts: the curvature and size of everyone's eyes are different, so when buying contact lenses, the curvature of the cornea should be measured, and contact lens lenses with different curvatures and diameters should be selected according to the curvature and diameter of the cornea. There are special requirements for lens power The power of contact lenses is different from that of glasses, and there is a conversion formula between the two, usually myopic people wear contact lenses with lower power than glasses, and the higher the degree of myopia, the greater the reduction required. For farsighted people, contact lenses are a little higher than those of glasses. (Recommended reading: Conversion of contact lens power and optometry power) Lens thickness and water content selection Some people are usually prone to eye fatigue and are prone to "dry eye", and the situation will be more serious when wearing contact lenses. The tear film of this type of person dries easily, and the tears evaporate quickly and absorb quickly. In this case, lenses with a low water content and medium thickness should be used, so that the water in the eye will evaporate a little less. (Recommended reading: The meaning and selection of various parameters of contact lenses) Lens material requirements vary Eyes need oxygen, and hypoxia can produce complications, and patients feel dry and bloodshot. Contact lenses act like a barrier to block oxygen from entering the eye, and the thicker the lens, the more powerful the blockage. The higher the prescription, the thicker the contact lenses, the more important it is to choose materials with good oxygen permeability. There are three key points to avoid infection Source: The source of contact lenses must be safe and quality-assured. Anyone else who has used it or what has expired cannot be used, otherwise the risk of corneal infection is greatly increased. Corneal infection can cause vision loss, so please go to the hospital for examination as soon as possible. Environment: Contact lenses need to be removed in some situations where they are not allowed to be worn, such as for cosmetic treatment, swimming, or showering, otherwise there is a high risk of infection or damage to the eyes. Nursing: If not cleaned and disinfected with the nursing solution in time, the virulence of the microflora is greater, and in the case of weak human resistance, pathogens are likely to infect the cornea from the tiny wounds in the eye. (Recommended reading: How to care for contact lenses)