2300-500 degrees, 1.60 can be considered, and a little finer can be considered 1.67.
3500- 1000 degrees, thinner, consider 1.7 1.
If the temperature is above 4 1000 degrees, consider 1.7 1, and if it is finer, it will be 1.74, as long as there is more money.
The interaction with the lens should be considered when selecting the frame: the larger the frame size, the larger the effective diameter of the frame, the larger the minimum lens blank required, and the thicker and heavier the lens after trimming.
Therefore, both high-altitude lenses and aspherical lenses need small, symmetrical, round or square frames, but frames with too long meridian are not suitable. Graduated lenses need a suitable frame height, that is, the vertical distance from the center of pupil to the bottom of the groove of the mirror ring is at least 22 mm
Extended data:
Protection of glasses
1, taking it off with one hand will destroy the left and right balance of the spectacle frame, resulting in deformation. I suggest you hold your temples with your hands and remove them in parallel on both sides of your cheeks.
2. Generally, the left temple is folded first when taking it, which is not easy to cause the deformation of the mirror frame.
3. It is suggested to rinse the glasses with clear water, absorb the water with a paper towel, and then try to wipe them with a special glasses cloth. It is necessary to hold the edge wire of the mirror frame on one side of the wiping mirror and gently wipe the lens to avoid damaging the mirror frame or lens with excessive force.
When you don't wear glasses, please wrap them in glasses cloth and put them in the glasses case. If temporarily placed, please put the convex surface of the glasses upward, otherwise it is easy to wear out the lenses. At the same time, glasses should avoid contact with insect repellent, toilet cleaning supplies, cosmetics, hair gel, medicines and other corrosive substances, and avoid long-term direct sunlight and high temperature (above 60℃), otherwise it will easily lead to deterioration, deterioration and discoloration of lenses and frames.
5. Go to the store regularly for plastic adjustment. The deformation of the mirror frame will burden the nose and ears, and the lens is easy to loosen.
6. Please don't use glasses during strenuous exercise, so as not to break the glasses due to strong impact, causing eye and face damage; Do not use worn lenses to prevent vision loss caused by scattered light; Please don't look directly at the sun or glare, so as not to hurt your eyes.
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