Why are the new glasses uncomfortable?
Why do you feel uncomfortable every time you change your glasses?
Do you know why?
Eyeglasses are a special kind of product. It is mainly aimed at improving eyesight, and requires clearness and comfort after wearing. However, in the process of fitting glasses, some customers often report that the new glasses are uncomfortable after wearing, and they always feel awkward, uncomfortable, and different from the original glasses. Check the technical specifications of the newly equipped glasses, such as diopter deviation, optical center horizontal deviation and vertical mutual difference, axial deviation, etc., all meet the requirements. If customers are allowed to adjust to days or even weeks, some people may accept it, while other customers may not accept such glasses even after adjusting for a period of time. Why?
This kind of phenomenon mostly happens to people who are not first-time opticians. In the process of serving them, old glasses also "reformed" their eyes, making the eyeballs more or less "abnormal." It is more difficult to wear glasses for him, but it is even more difficult to wear a suitable pair of glasses. Some people have been refusing to update with glasses that look very old and think they are quite comfortable, because they have tried to update but it is difficult to adapt to the new glasses. The longer the history of wearing mirrors, the more prominent the person with the deeper degree. In fact, comparing the differences between the new and old glasses can find out the crux of the problem.
1. The effect of the horizontal distance between the optical center and the deviation of the interpupillary distance
Under normal circumstances, the smaller the deviation between the optical center distance and the interpupillary distance, the better, so that the assembly is scientific and comfortable after wearing. If the patient's glasses have a large horizontal deviation of the optical center and the degree is higher (the deviation between the optical center horizontal distance and the interpupillary distance is required for different refractive conditions. The new lens is equipped with the optical center position according to the standard interpupillary distance. May feel uncomfortable, such as dizziness, bent eyesight, and less than one eye. The greater the diopter, the more obvious the reaction. Therefore, when fitting glasses for customers, the horizontal distance between the optical center of the old glasses and the interpupillary distance should be measured first. The size of the deviation, calculate the size of the prism at the corresponding pupil, and use it as a reference for displaying a new lens. On the other hand, when using myopic muscles to adjust myopia, it is easy to cause visual fatigue and increase the development of depth. The use of transitional optical heart distance, Not suitable for older people, it is best to keep the original state, so as not to cause discomfort and other problems.
Second, the influence of the inclination of the legs of the frame
The inclination of the frame body leg refers to the angle between the plane normal of the mirror body and the temple. Generally there are 6 degrees, 8 degrees, 10 degrees, several specifications. Due to many non-standard spectacle frames and the deformation of the spectacle frames during the wearing of glasses, this has formed the influence of the inclination size on the visual habits. Because the position of the temple is mostly connected to the upper half of the rim of the spectacle frame, and due to the gravity of the glasses themselves, the position of the optical center of the spectacle lens shifts when worn. For this situation, one solution is to allow the patient to adapt as much as possible, and the other method is to adjust the inclination of the leg appropriately so that it is close to the original mirror when the patient is unable to adapt.
Three: optical center asymmetry
For some patients with large degrees and long history of wearing glasses, the asymmetry of the optical center of the old lens will hinder the wearing effect of the new lens. When fitting glasses, the optical center symmetry of the old glasses should be measured, and the diopters should be referenced to calculate the influence of the prism degree at the corresponding pupil. The lens can be made according to the state of the old glasses of the patient. This is especially important for some elderly patients, because it is not easy to change a long-term wearing spectacle. These so-called substandard glasses conform to the eye state of the patient, and the patient will be more comfortable and natural to wear. For young patients with low degrees and short history of wearing glasses, they should be allowed to wear glasses formulated according to the standard.
4. The impact of overcorrection
It is generally required that myopia correction vision reach 5.0, and excessive correction will pay attention to the amount of eye muscle adjustment when near objects, causing further fatigue of vision and diopter. Therefore, when the original lens is over-corrected and the corrected vision is 5.2 or higher, it should be adjusted to 5.0 when wearing a new lens. In this way, some patients will feel discomfort due to diopter reduction when wearing the new lens, such as strenuous vision, etc. At this time, they can be matched to a normal state of 5.0 according to the actual situation.
Fifth, the influence of lens curvature and astigmatism axis difference
A person who wears 600 bends and -5.00D for many years can hardly adapt to lenses with 300 bends or lower. For glasses with astigmatism, the discomfort caused by the difference between the astigmatism axis of the new mirror and the old mirror cannot be ignored. Although the new mirror axis position may be the clearest visual position, it is not necessarily a position that is comfortable for the patient. Therefore, when the patient cannot adapt to the new axis position and has little effect on the corrected vision, it can be directly prepared according to the same axis position.
6. Impact in other areas
1. Influence of lens material
Due to the difference in refractive index, light transmittance, Abbe's coefficient and other performance indexes of materials such as light white film, ultra-thin film, and resin film, the wearing effect is different for the same diopter. For example, some people feel dizzy as soon as they wear ultra-thin flakes.
2. The effect of the position of the nasal pads of the spectacle frame on the visual effect
The position of the nose pad can directly affect the relative position of the optical center and the pupil and the distance from the vertex of the lens to the cornea, which also affects the actual vision effect.
For positive lenses to correct hyperopia, the effective refractive power of the spectacle lens for the eye increases as the distance from the posterior vertex to the cornea increases, and decreases as the distance from the posterior vertex to the cornea decreases. For myopia corrected by negative lenses, the effective refractive power of the spectacle lens for the eye then decreases from the apex to the cornea, and then decreases from the apex to the cornea.
3. The impact of internal dispersion and external dispersion
The image quality of internal dispersion lenses is superior to external dispersion lenses, so people who are used to internal dispersion lenses may feel uncomfortable if they change to external dispersion lenses. China Spectacles Trading Network is an e-commerce platform focused on spectacle frames under China Net Library, which gathers all the upstream and downstream enterprises in the country to purchase and wholesale. Provide consumers with professional glasses frame trading platform and information. So those who want to buy, hurry up and buy it! The above information is from China Spectacles Trading Network:
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