Abstract: when ordinary consumers choose glasses frames, they often only pay attention to the problem of beauty. In fact, the optical and metrological technical indicators of glasses frames are very important for consumers’ comfort in wearing glasses. The selected frame must meet the optical and metrological requirements., 1. The geometric center size of the spectacle frame should preferably be close to the distance between the pupils of both eyes (it is better to be less than 4-10mm). Considering that the blank of the lens must be moved to the center and cut before it can be installed on the frame and placed in front of you, it is better to have the pupil directly facing the geometric center of the spectacle frame, preferably less than 4-10mm. If the center of the lens is very large, it may cause prism and other effects and affect the comfort of wearing glasses. 2. Ensure the lens after wearing the lens The distance to the eyeball is about 10mm., If the lens is too far away from the eye, not only the optical effect will change, but also the wearer will see the outside of the lens, resulting in difficult positioning; If the lens is too close to the eye, the eyelashes will touch the lens, which is not only easy to blur the lens, but also cause irritation. Therefore, after wearing glasses, it is best to ensure that the distance from the lens to the eyeball is about 10mm., 3. The included angle between the front mirror of glasses and the vertical line of the wearer’s face is about 4 ° ~ 18 °., The size of the angle is related to the field of view. Generally speaking, the upper part of the frame cannot touch the eyebrows, and the lower part cannot touch the face. If the frame can not reach the required forward tilt angle, it is recommended to find a professional to adjust the nose bracket or change a pair of frame., 4. The width of spectacle nose frame is moderate., When consumers choose the spectacle frame, they can check it by themselves through the following methods: keep the head vertical and look forward, and the spectacle frame can maintain a satisfactory position without any clamping of the spectacle legs.,
1. The geometric center size of the spectacle frame should preferably be close to the distance between the pupils of both eyes (preferably less than 4 to 10 mm).
Considering that the blank of the lens must be moved to the center and cut before it can be installed on the lens frame and placed in front of you, the position of the pupil should be facing the geometric center of the eyeglass frame, preferably less than 4 ~ 10mm. If the lens shift center is very large, it may cause prism and other effects, affecting the comfort of wearing glasses.
2. After wearing glasses, ensure that the distance from the lens to the eyeball is about 10mm.
if the lens is too far away from the eye, not only the optical effect will change, but also the wearer will see the outside of the lens, resulting in difficult positioning; If the lens is too close to the eye, the eyelashes will touch the lens, which is not only easy to blur the lens, but also cause irritation. Therefore, after wearing glasses, it is best to ensure that the distance from the lens to the eyeball is about 10mm.
3. The included angle between the front mirror of glasses and the vertical line of the wearer’s face is about 4 ° ~ 18 °. The angle of
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is related to the field of view. Generally speaking, the upper part of the frame cannot touch the eyebrows, and the lower part cannot touch the face. If the frame can not reach the required forward tilt angle, it is recommended to find a professional to adjust the nasal bracket or change a pair of frame.
4. The width of spectacle nose frame is moderate.
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consumers can check the spectacle frame themselves by the following methods: keep the head vertical and look forward, and the spectacle frame can maintain a satisfactory position without any clamping of the spectacle legs.
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if the nose bridge frame is too narrow, not only will the lens be too high in front of your eyes, but also the contact part between the nose bridge frame and the nose will be uncomfortable, and even cause temporary depression of nose skin tissue; If the nose bridge frame is too wide, the lens will fall too low, and the lens leg cannot keep the spectacle frame in its normal position for a long time.
5. The length of glasses legs is moderate.
in principle, the curved part of the mirror leg should be just above the ear fold, but the pressure on the ear fold should be avoided.
if the leg length is not enough, the glasses will tilt upward, and the tail of the glasses frame will press into the back of the ear, making the wearer uncomfortable; If the length of the lens leg is too long, when the head tilts, the tail of the glasses frame will contact the back of the ear, and the glasses will fall down by themselves.
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it is worth noting that when trying on the spectacle frame and estimating the length of the spectacle legs, the frame should maintain a correct forward tilt angle on the face. If the forward tilt angle is not taken into account when trying on, the length of the spectacle legs will be too short for a long time.
6. The deeper the negative diopter (commonly known as myopia degree), the smaller the lens circle is better.
7. Generally speaking, circular frames are not suitable for those with large astigmatism.
8. Considering the effects of visual aberration and prism, ordinary consumers had better not choose frames with too large arc.
9. For children, you can choose a transparent mirror frame without nose pad. If the nose pad is too high, it will show the characteristics of collapsed nose bridge.
in addition, it is worth reminding that if consumers often wear glasses with metal frames and suddenly replace them with plastic frames, or vice versa, they will feel uncomfortable when they just wear them. This is because metal frames generally have nose supports. With nose supports, you can adjust the vertical distance between the lens and the eyeball. Often wearing metal frames will be more suitable for the distance of metal frames, while plastic frame frames have no nose supports, so the distance can not be adjusted. You will feel uncomfortable when you just wear them. Generally, about a week is the adaptation period. After the adaptation period, the discomfort will gradually disappear or significantly reduce. If it still does not reduce, it is recommended to find a professional for consultation or reuse the original frame.
some tips for selecting glasses frames
when selecting glasses frames, you can pay attention to the appearance and feel of glasses frames.
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consumers can first look at the quality of the frame in general from the overall refinement, smoothness, spring recovery and flexibility of the leg opening, and then pay attention to comprehensively judge the quality of the frame in terms of screw tightness, solder joint process, symmetry of the frame, standardization of dimensions and other details.
pay attention to the trial wearing process when selecting the spectacle frame.
try wearing the spectacle frame, not only pay attention to whether it is beautiful, but also pay attention to whether the spectacle frame meets the optical and metrological requirements, whether it matches the facial bone structure of the wearer, whether each force point on the face maintains uniform force and stable support, and whether it can keep the lens in a reasonable position all the time, Comfortable to wear.