Which contact lenses are better?
Compared with frame glasses, many young people prefer to wear contact lenses that are convenient and good-looking. So, which kind of contact lenses is better, let's first understand the parameters of contact lenses.
Generally, the higher the water content, the softer and more comfortable the lens, and the higher the oxygen permeability. However, after wearing contact lenses with high water content, the water in the eyes will evaporate faster, and because tears must make up for this part of the missing water, it is also easy to cause dry eyes.
The oxygen permeability of contact lenses is expressed by the oxygen permeability coefficient, which mainly depends on the material of the lens. The oxygen permeability of the hydrogel contact lens is proportional to the water content, while the silicone hydrogel contact lens contains two channels of silicon and water to transport oxygen, which greatly improves the oxygen permeability of the lens.
The life cycle of contact lenses can be divided into short cycle and long cycle. Among them, the short cycle usually refers to the daily throw, monthly throw, etc., and the long period usually refers to the annual throw, half-year throw and so on. Long-term lenses have good shape and toughness, which is convenient for first-time wearers to wear. Short-cycle lenses tend to have higher water content, so they are more likely to absorb and precipitate, and must be carefully cleaned. If you use a daily disposable, you can take it off and throw it away, which minimizes the risk of eye infections.
The base arc of contact lenses is overwhelmingly between 8.5-8.7, which is also in line with the base arc range for most wearers. If the base arc is too large, it will lead to sliding film, and if the base arc is too small, it will affect the corneal breathing. The general error is within 0.2mm, and you can choose contact lenses that are slightly larger than the base arc of your eyes.
There are many parameters and types of contact lenses, so it is impossible to simply evaluate which contact lens is the best. It is important to choose the lens that suits you.