Most Eyeglasses Lenses Are Thin In The Middle
The discount eyeglasses online matching is becoming increasingly common, but there are always many people who encounter various problems after buying them: even though the refractive index is quite high, how can they still get them so thick? Why is it so uncomfortable to wear Firstly, we need to know which factors affect the thickness of the lens.
As is well known, the higher the degree, the thicker the lens thickness. Refractive index: refers to the numbers we often hear, such as 1.56, 1.6, and 1.74. The higher the refractive index, the thinner the lens.
Everyone understands the size of the frame, as most lenses become thicker on both sides. From this, it can be concluded that the larger the discount eyeglasses online frame, the thicker the edge thickness.
The ideal size for choosing a frame should be as follows: frame width+nose bridge width=pupillary distance. The data of mirror width and nose width are all present on the frame.
So why is the thickness of the lens affected by this? Because most discount eyeglasses online lenses are thin in the middle and thick on both sides. If the width of the glasses plus the height of the nose are exactly equal to the distance between the pupils, then the thinnest position of this pair of glasses is at the center. Otherwise, there will be a deviation, causing the lens to be taken away from the center position (i.e. thicker areas) during use.
The material of the lens is self-evident. Astigmatism degree, the same degree of glasses, why are some people's lenses thin, some people's lenses thick, and some are the reason for this.
When the prescription of glasses is incorrect, wearing them naturally feels uncomfortable. If the distance between the pupils of the glasses is not done correctly, it can also be uncomfortable.
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