If you are highly myopic, do you often wear thick glasses and feel dull? Many people with high myopia want to know how to get a pair of lightweight and thin glasses.
I have been engaged in the optician industry for more than ten years, so let me summarize the factors that affect the thickness of lenses.
Customers always ask, how thick are my lenses? Believe me, I want to know how many millimeters thick it is after mixing more than you. But I really can't tell. The reasons are as follows:
1) Frame size. Assuming that a customer's interpupillary distance is 60, if the interpupillary distance of the frame (that is, the distance between the geometric centers of the two pieces) is 70, divided by 2, it is the amount that the center point should be moved by 5 mm. The amount of shifting is the real factor that essentially determines the thickness. Myopia is thin in the center and thick at the edges. So the more you get to the edge, the thicker it is.
2) The size of the interpupillary distance. Assuming that the interpupillary distance of the frame is 70, the heart movement amount of the person with the 68 pupil distance is only 1, and the heart movement amount of the person with the 58 pupil distance is 6. When other factors remain unchanged, the natural interpupillary distance is small and thick.
3) The degree is high or low. Everyone understands this, so I won't say more.
4) 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 with the same degree of the lens blank. Generally -0.00-4.00 is more suitable for 1.56, -3.00-6.00 is more suitable for 1.60, -4.00-8.00 is more suitable for 1.67, and above -6.00 is suitable for 1.74. Of course, local tyrants can match 1.74 with a flat light without any problems. -6.00 degree 1.74 is generally about 25-30% thinner than 1.56.
5) Frame material. The frame of the plate is generally thicker, and the metal material is generally thinner. If other factors remain unchanged, it should be the same after the actual processing, but the thick plate material can cover part of the thickness of the lens, and it does not look so thick.
6) If there is astigmatism, the closer the axial position is to 180, the thinner it will be. For people with high astigmatism, the axial position of 180 has little effect on the thickness. But the 90-axis position has a great influence on the thickness.
7) The round ones are thinner than the square ones. The round ones are not as angular as the square ones, and the thicker ones will indeed look thinner, but the effect is not significant.
8) The size of the lens. If the frame size is the same, the interpupillary distance is the same, but if the sheet shape is small. Just take a smaller lens part, and it will be thinner when ground.
9) The central thickness of the lens: The central thickness is specified to be no 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. Consumers don't need to pay attention to this. People in the industry need to understand.
So if you ask “I am highly myopic. If I don’t consider my wallet, how can I choose a pair of thinner glasses?”
I will give you an answer:
1) If your interpupillary distance is 66mm, the size of the shelf should also be 66mm, which is the most ideal and the thinnest, that is to say, the shelf should be small. If the interpupillary distance is very small and only 58, if you choose the frame of 58, most people will be small and squeeze the face. We can only choose a shelf that is as small as possible without squeezing the face. People with high myopia, small interpupillary distance, and large face are more difficult from the perspective of glasses, and the range of frames that can be selected is even smaller, which is why it is difficult for people with high myopia to choose a good-looking frame. willing one.
2) Choose a 1.74 resin lens for the lens. If other data remain unchanged, the higher the refractive index, the thinner the lens. Of course, 1.9 glass is the thinnest, but the disadvantage of glass is that it is heavy, easily broken, and unsafe, so there are few people who deserve it.
3) Ask the processing master to pour more edges, and the effect will be better if it is more beautiful and thin. But if there are too many inverted edges, it will be more obvious when viewed from the front.
