I don’t know if you encounter such a problem when choosing the prescription of contact lenses. Obviously, the choice is based on the prescription of the frame glasses, but there are often unclear situations. What is the reason?

First of all, we need to understand the difference between contact lenses and frame glasses: there is a certain distance between the lens of frame glasses and the cornea, which we call the eye-to-eye distance, generally 12mm. And contact lenses are worn on the cornea without the existence of this distance, so the aberration, distortion, and chromatic aberration caused by this distance will be reduced.

There is purely a conversion formula between the degree of contact lenses and the degree of frame glasses, the diopter of contact lenses = the diopter of frame glasses ÷ (1- 0.012× the diopter of frame glasses). The results obtained according to the formula can be briefly summarized as follows:

1. If the degree of myopia is below 400 degrees (excluding 400 degrees) and there is no astigmatism, you can choose the degree of contact lenses directly according to your own frame degree.

2. If the myopia is more than 400 degrees, it needs to be appropriately reduced according to the degree of different stages. From 400 to 550 degrees, reduce by 25 degrees, from 550 to 725 by 50 degrees, from 750 to 850 by 75 degrees, from 875 to 1000 by 100 degrees.

3. If you find that a certain degree is not available when converting the contact lens degree, you can choose a similar degree. For example, after 800 degrees are reduced by 75 degrees, it is 725 degrees. If there is no 725 degrees, you should choose 700 degrees, and so on. In general, choosing a lens with a slightly lower power will be more comfortable to wear than a slightly higher lens.

After the degree of contact lens is clear, it is the choice of lens material. We recommend to you the third-generation silicone hydrogel contact lenses developed by pharnorcia's expert team for many years. Pharnorcia's top experts have changed the oxygen-impermeable properties of the original hydrogel material through silicon hydrogel. Traditional hydrogel lenses only have "water channels" and one oxygen transmission channel, but pharnorcia silicon hydrogel lenses have "water channels". And "silicon channel" two oxygen delivery channels, which allow oxygen to pass through more smoothly, greatly improving the oxygen permeability. In addition to high oxygen permeability, Pharnorcia's third-generation silicone hydrogel breaks through the contradiction between water content and oxygen permeability of the hydrogel because it does not rely on water as an oxygen-permeable medium, and avoids dry eyes when wearing it. At the same time, it can meet consumers' requirements for aesthetics and convenience.

Choose the appropriate prescription and the best material, and pharnorcia silicone hydrogel contact lenses can bring a senseless experience of breathing freely to your eyes.

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