Abstract: the inclination of mirror frame body leg refers to the included angle between the plane normal of mirror body and mirror leg. There are generally 6 degrees, 8 degrees, 10 degrees and several specifications. Due to many non-standard spectacle frames and the deformation of spectacle frames during wearing, the influence of inclination on visual habits is formed., Glasses are a special commodity. It is mainly aimed at improving eyesight. It is required to be clear and comfortable after wearing. In the process of glasses matching, the technical indexes of new glasses, such as diopter deviation, optical center horizontal deviation, vertical mutual difference, axial deviation, etc., meet the requirements, but the customer always feels uncomfortable and uncomfortable after wearing the new glasses, which is different from the original glasses. Some customers need to adapt for a few days or even weeks, while some customers still can’t accept such glasses even after adapting for a period of time. Why? This phenomenon often occurs in people who are not first-time photographers. Old glasses have also “transformed” their eyes in the process of serving them, making them more or less “abnormal”. It’s difficult to match his glasses, especially with a pair of suitable glasses. Some people always wear glasses that look very old and think they are quite comfortable, but refuse to update them because they have tried to update but can’t adapt to the new glasses. The longer the history of wearing glasses and the deeper the degree, the more prominent it is. Zhang Liang glasses studio, professional ophthalmologists provide you with the best personalized glasses matching scheme. In fact, we can find out the crux by comparing the different states of new and old glasses., I. Influence of optical center horizontal distance and pupil distance deviation. Under normal circumstances, the smaller the deviation between optical center distance and pupil distance, the better. In this way, the assembly is scientific and comfortable. If the optical center level deviation of the patient’s previous glasses is large and the degree is high, the optical center position of the new glasses is determined according to the standard pupil distance. After wearing, the patient is likely to feel uncomfortable, such as dizziness, visual curvature, and less than one left and right eyes. The greater the diopter, the more obvious the response. Therefore, when matching glasses for customers, first measure the deviation between the optical center horizontal distance of old glasses and pupil distance, and calculate the prismatic degree at the corresponding pupil as a reference for displaying and matching new glasses. For example, the pupil distance of a patient is 63mm, the left and right lenses of the original lens are -4.00, and the optical distance is 75mm. The degree of new glasses is -5.00d. That is to say, the distance between the optical center of each lens and the corresponding pupil is 6mm, and the pupil of the original lens is equivalent to adding a bottom inward force of 2.4 Δ A prism. If the new glasses remain in the original state, The optical center distance shall be 63+ (2.4 / 5)? 0? = 73mm. However, from the perspective of protecting the patient’s vision and eye hygiene, the new lens should be compromised with reference to the optical center distance and pupil distance of the original lens. For example, it can be assembled into 69mm as the transition optical center distance. On the one hand, too large optical center distance is easy to cause exophoria of the eyeball. On the other hand, it is often adjusted by ocular muscles when looking at myopia, which is easy to cause visual fatigue and deepen the degree development. Transition optical center The use of distance is not suitable for older people. It is best to keep the original state so as not to cause discomfort and other problems., II. The influence of the inclination of the mirror frame body and legs. The inclination of the mirror frame body and legs refers to the included angle between the plane normal of the mirror body and the mirror legs. There are generally 6 degrees, 8 degrees, 10 degrees and several specifications. Due to many non-standard spectacle frames and the deformation of spectacle frames during wearing, the influence of inclination on visual habits is formed. For example, for a person who is used to wearing glasses with a body leg inclination of 0 degrees, if the body leg inclination of his new glasses is 10 degrees, even if the degree and optical distance are the same as those of the original glasses, he may suffer from dizziness, inaccurate up and down positioning and other symptoms. Since the position of the glasses legs is mostly connected to the upper half of the lens ring of the glasses frame, and due to the gravity of the glasses themselves, the optical center position of the glasses is offset when wearing. In this case, one solution is to let the patient adapt as much as possible, and the other is to properly adjust the leg inclination to make it close to the original mirror when the patient cannot adapt., Optical center asymmetry includes the existence of horizontal asymmetry and vertical mutual difference, which is generally greatly affected by vertical mutual difference. Diopter at 25 to 00, the maximum vertical difference is allowed to be 1.5mm. Greater than or equal to At 25d, only 1mm is allowed. Of course, when the degree is large, the influence of horizontal asymmetry is also quite serious. For some patients with large degree and long wearing history, the asymmetry of optical center of the old mirror will hinder the wearing effect of the new mirror. When matching glasses, the optical center symmetry of old glasses shall be measured, and the influence of prismatic degree at the corresponding pupil shall be calculated with reference to its diopter. The glasses can be made according to the state of the patient’s old glasses. This is particularly important for some elderly patients, because it is not easy to change a long-term habit of wearing glasses. This so-called substandard glasses, but in line with the patient’s eye state, the patient will be more comfortable and natural to wear. For young patients with low degree and short history of wearing glasses, they should be allowed to wear glasses prepared according to the standard., III. The impact of over correction. Generally, myopia correction vision is required to reach 5.0. Over correction will pay more attention to the adjustment of ocular muscles near objects, resulting in visual fatigue and further deepening of diopter. Therefore, when the original mirror is over corrected and the corrected visual acuity reaches 5.2 or higher, it should be adjusted to 5.0 when a new mirror is equipped. In this way, some patients will feel uncomfortable due to reduced diopter when wearing new glasses, such as difficulty in seeing things. At this time, they can be matched to a normal state of 5.0 according to the actual situation.,
glasses are a special commodity. It is mainly aimed at improving eyesight. It is required to be clear and comfortable after wearing. In the process of glasses matching, the technical indexes of new glasses, such as diopter deviation, optical center horizontal deviation, vertical mutual difference, axial deviation, etc., meet the requirements, but the customer always feels uncomfortable and uncomfortable after wearing the new glasses, which is different from the original glasses. Some customers need to adapt for a few days or even weeks, while some customers still can’t accept such glasses even after adapting for a period of time. Why? This phenomenon often occurs in people who are not first-time photographers. Old glasses have also “transformed” their eyes in the process of serving them, making them more or less “abnormal”. It’s difficult to match his glasses, especially with a pair of suitable glasses. Some people always wear glasses that look very old and think they are quite comfortable, but refuse to update them because they have tried to update but can’t adapt to the new glasses. The longer the history of wearing glasses and the deeper the degree, the more prominent it is.Zhang Liang glasses studio, professional ophthalmologists provide you with the best personalized glasses matching scheme. In fact, by comparing the different states of new and old glasses, we can find out the crux.
I. Influence of the deviation between the horizontal distance of the optical center and the pupil distance
under normal circumstances, the smaller the deviation between the optical center distance and the pupil distance, the better, so that the assembly is scientific and comfortable after wearing. If the optical center level deviation of the patient’s previous glasses is large and the degree is high, the optical center position of the new glasses is determined according to the standard pupil distance. After wearing, the patient is likely to feel uncomfortable, such as dizziness, visual curvature, and less than one left and right eyes. The greater the diopter, the more obvious the response. Therefore, when matching glasses for customers, first measure the deviation between the optical center horizontal distance of old glasses and pupil distance, and calculate the prismatic degree at the corresponding pupil as a reference for displaying and matching new glasses. For example, the pupil distance of a patient is 63mm, the left and right lenses of the original lens are -4.00, and the optical distance is 75mm. The degree of new glasses is -5.00d. That is to say, the distance between the optical center of each lens and the corresponding pupil is 6mm, and the pupil of the original lens is equivalent to adding a bottom inward force of 2.4 Δ A prism. If the new glasses remain in the original state, The optical center distance shall be 63+ (2.4 / 5)? 0? = 73mm. However, from the perspective of protecting the patient’s vision and eye hygiene, the new lens should be compromised with reference to the optical center distance and pupil distance of the original lens. For example, it can be assembled into 69mm as the transition optical center distance. On the one hand, too large optical center distance is easy to cause exophoria of the eyeball. On the other hand, it is often adjusted by ocular muscles when looking at myopia, which is easy to cause visual fatigue and deepen the degree development. Transition optical center The use of distance is not suitable for older people. It is best to keep the original state so as not to cause discomfort and other problems.
II. The influence of the inclination of the frame body and legs
the inclination of the frame body and legs refers to the included angle between the plane normal of the mirror body and the mirror legs. There are generally 6 degrees, 8 degrees, 10 degrees and several specifications. Due to many non-standard spectacle frames and the deformation of spectacle frames during wearing, the influence of inclination on visual habits is formed. For example, for a person who is used to wearing glasses with a body leg inclination of 0 degrees, if the body leg inclination of his new glasses is 10 degrees, even if the degree and optical distance are the same as those of the original glasses, he may suffer from dizziness, inaccurate up and down positioning and other symptoms. Since the position of the glasses legs is mostly connected to the upper half of the lens ring of the glasses frame, and due to the gravity of the glasses themselves, the optical center position of the glasses is offset when wearing. In this case, one solution is to let the patient adapt as much as possible, and the other is to appropriately adjust the leg inclination to make it close to the original mirror when the patient cannot adapt. The optical center asymmetry of
and
includes the existence of horizontal asymmetry and vertical mutual difference, which is generally greatly affected by vertical mutual difference. Diopter at 25 to 00, the maximum vertical difference is allowed to be 1.5mm. Greater than or equal to At 25d, only 1mm is allowed. Of course, when the degree is large, the influence of horizontal asymmetry is also quite serious. For some patients with large degree and long wearing history, the asymmetry of optical center of the old mirror will hinder the wearing effect of the new mirror. When matching glasses, the optical center symmetry of old glasses shall be measured, and the influence of prismatic degree at the corresponding pupil shall be calculated with reference to its diopter. The glasses can be made according to the state of the patient’s old glasses. This is particularly important for some elderly patients, because it is not easy to change a long-term habit of wearing glasses. This so-called substandard glasses, but in line with the patient’s eye state, the patient will be more comfortable and natural to wear. For young patients with low degree and short history of wearing glasses, they should be allowed to wear glasses prepared according to the standard.
III. impact of over correction
generally requires myopia corrected vision to reach 5.0. Over correction will pay more attention to the adjustment of ocular muscles near objects, resulting in visual fatigue and further deepening of diopter. Therefore, when the original mirror is over corrected and the corrected visual acuity reaches 5.2 or higher, it should be adjusted to 5.0 when a new mirror is equipped. In this way, some patients will feel uncomfortable due to reduced diopter when wearing new glasses, such as difficulty in seeing things. At this time, they can be matched to a normal state of 5.0 according to the actual situation.
IV. influence of lens curvature and astigmatism axis position difference
a person who has worn 600 bends and -5.00d for many years is difficult to adapt to 300 bends or even lower. For glasses with astigmatism, the maladjustment caused by the difference of astigmatism axis between the new mirror and the old mirror can not be ignored. Although the axial position of the new mirror may be the most clear position, it is not necessarily the position that makes the patient feel comfortable. Therefore, when the patient cannot adapt to the new axial position and has little impact on the corrected vision, the axial position can be prepared directly.
v. influence from other aspects
1. The influence of lens material. Due to the different refractive index, transmittance, Abbe coefficient and other performance indexes of optical white film, ultra-thin film and resin film, the wearing effect is also different for the same diopter. For example, some people feel dizzy when they wear ultra-thin films, while they feel no discomfort when they wear light white films.
2. The influence of the position of the nose rest of the spectacle frame on the visual effect. The position of the nose rest can directly affect the relative position between the optical center and the pupil and the distance from the vertex behind the lens to the cornea, which also affects the actual visual effect.
and
for the correction of hyperopia with positive lenses, the effective diopter of glasses increases with the increase of the distance from the rear vertex of the lens to the cornea, and decreases with the decrease of the distance from the rear vertex of the lens to the cornea. For the correction of myopia with negative lenses, the effective diopter of glasses to the eye decreases with the increase of the distance from the vertex to the cornea, and then increases with the decrease of the distance from the vertex to the cornea.
3. The influence of internal and external astigmatism. The imaging quality of internal astigmatism lens is better than that of external astigmatism lens, so people who are used to internal astigmatism lens may feel uncomfortable once they change to external astigmatism lens.