Factors that affect the thickness of the lens
22-09-14 11:31:17 By Bestsea eyewear
In some of our previous articles, we have talked about some knowledge about Acetate Eyewear, Metal Eyewear and Titanium Eyewear in detail, which gives us a deeper understanding of Eyewear. But for many people who wear myopic glasses, it is very important to have a pair of light and thin glasses. After all, glasses must be worn on the face often, and if they are heavy, they will be very uncomfortable. So how can you choose a pair of light and thin myopia lenses? This article mainly summarizes several factors that affect the thickness of spectacle lenses.
Factor 1 that affects the thickness of the lens: the size of the spectacle frame. Assuming a customer's interpupillary distance is 60, if the frame's interpupillary distance (that is, the distance between the geometric centers of the lenses) is 70, dividing by 2 means that the center point should be moved by 5mm. The amount of heart shift is what really determines the thickness in essence. Myopic films are thin at the center and thick at the edges. So it gets thicker to the edge. In theory, the closer your interpupillary distance is to the frame's interpupillary distance, the better. For example, the interpupillary distance of the spectacle frame is 70, the interpupillary distance of a person is 68, and the displacement is only 1mm, while the displacement of a person with an interpupillary distance of 58 is 6mm. When other factors remain unchanged, the natural interpupillary distance is small and thick.
Factor 2 that affects the thickness of the lens: the degree of myopia. This is understood by everyone, because in the case of the same material and parameters of the lens, the higher the degree, the thicker the lens, and the heavier the glasses frame.
Factor 3 that affects the thickness of the lens: refractive index. Generally, the refractive index is divided into 1.56, 1.60, 1.67, and 1.74. The larger the number, the thinner the lens. Of course, the prices are also different. The higher the refractive index of the same brand and the same material, the more expensive the price is.
Factor 4 that affects the thickness of the lens: frame material. The material of the frame is also one of the most important factors affecting the thickness of the frame. Acetate glasses are generally thicker and heavier, and metal glasses are generally thinner, especially titanium glasses. Due to the strength and toughness of titanium materials, they can be made light and thin. Of course, when matching lenses, you can't completely look at the material of the frame, but also whether it is suitable for the thickness of the lens. For example, if you have a high degree and you have to choose a relatively thicker lens, it is not suitable to choose a very thin eyewear frame. Thin glasses, otherwise it will look very uncoordinated.
Factor 5 that affects the thickness of the lens: A round frame looks thinner than a square frame. The round frame is not like the square with corners. After the lens is installed, the surrounding looks more uniform, and it will appear thinner visually. But the impact is not great.
Factor 6 that affects the thickness of the lens: the size of the lens. If the frame size is the same, the interpupillary distance is the same, but the lens shape is smaller. Just take a smaller lens part, which looks thinner. Conversely, if you choose a larger frame, the edges of the lenses will also be thicker, which will also make the glasses appear thicker.
In addition, if you feel that the edge of the lens is too thick when you are wearing myopia glasses, you can also ask the processing master to make the V-shaped edge of the lens a little oblique, which will also appear thinner. Of course, if the side is too oblique, it will show too much whiteness from the front, and it will also affect the appearance. It depends on how you choose.
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