Why are the thicknesses of the lenses different?

Before that, we have talked about the acetate eyewear, metal eyewear, titanium eyewear in detail, including the related knowledge of wood eyewear and buffalo horn eyewear later. Now more and more people with myopia, when conditions permit, myopia patients want to wear a pair of light and thin glasses. Wearing thin and light glasses for a long time will not press the nose and tire the ears. So why is the thickness of the lens different? Below I have roughly summarized several aspects that affect the thickness of the lens, please watch.

1: The size of the glasses frame. Assuming your interpupillary distance is 60, and the frame's interpupillary distance is 70, divide by 2 and you should move the center point by 5mm. The amount of heart shift is what really determines the thickness in essence. Myopic lenses are thin at the center and thick at the edges. So the more you get to the edge, the thicker you get. In theory, the closer your interpupillary distance is to the frame's interpupillary distance, the better.

2: The degree of myopia. When the lens is the same as the material, the higher the degree, the thicker the lens.

3: Refractive index. Generally, the refractive index is divided into 1.56, 1.60, 1.67, and 1.74. In the case of the same degree of myopia, the larger the refractive index, the thinner the lens.

4: Frame material. acetate optical are generally thicker and heavier, and metal materials are generally thinner, especially titanium eyewear, which are the lightest. Of course, when choosing a lens, you can't completely look at the material of the frame. The frame you choose should be suitable for the thickness of the lens. For example, if you have a high degree of myopia, even if you choose the lens with the highest refractive index, the thickness of the lens is still there. At this time, it is not suitable to choose a thin and light frame, otherwise it will look very uncoordinated.

5: The style of glasses. Round frames look thinner than square ones. The round shelf has no corners around it. After the lens is installed, the surrounding area looks more uniform and visually thinner.

6: The size of the lens. If the frame and interpupillary distance are the same, the lens is smaller and looks thinner. Conversely, if you choose a larger frame, the edges of the lenses will be thicker, which will also make the eyewear appear thicker.

7: The center thickness of the lens: it is stipulated that the center thickness cannot be less than 1.0 mm for safety. If one manufacturer is 1.1 and another manufacturer is 1.2, then the actual thickness of different lenses will be different.