How to distinguish contact lens is yearly lenses or half year lenses?
Annual and half year throwing lenses belong to the type of contact lenses with relatively long service cycle, also known as "traditional lenses". As the packaging of the two is often similar, in order to avoid overdue use, we must make a good distinction.
All information of the product is marked on the package and instruction manual. The contact lenses with an annual service life of 1 year and a half year service life of 6 months are disposable. Generally, the parameters of annual and half year products of the same brand and series may not differ greatly, but the contact lenses of different brands and series will have great differences. The eye data can be obtained in the examination and evaluation before matching, and the annual or half year contact lenses can be selected by comparing the parameters.
So, why do we have to divide the annual and half year throwing in such trouble? On the basis of meeting the individual needs of consumers, the requirements for contact lens materials are different in different abandonment periods, which will affect product composition and lens life. Moreover, the lipid and protein in the tear are easy to adhere to the lens. Although most of the precipitates can be removed by daily scrubbing, a few will gradually deposit in the material gap, reducing the permeability and comfort of the lens. Therefore, considering all kinds of parameters of the lens, we can get the scientific use time, which can make the contact eyes more safe to wear.
The annual throwing has a good shape, low water content and a long service life of one year. It has a high cost performance, so it has been favored by many people. However, some people think that the half year throwing shortens the service life, reduces more protein deposition, and is relatively healthier. It is true that there are advantages and disadvantages in annual and semi annual sales, but the main materials will not be very different, so you can buy them on demand.