Optometry Articles

Is the effect of juvenile myopia control progressive tablets really so good? 

Can you really effectively control the development of myopia? 

Is it suitable for every student to wear juvenile myopia control progressive film? 

Is it also suitable for astigmatism? 

Does it have any side effects on visual methods? 

Can exophoric strabismus also be used? 

Is the near visual function of long-term wearers normal? 

What about the regulation of positive and negative relativity? 

Does it affect the normal fusion function of human eyes? 

What kind of people are most suitable for wearing juvenile myopia control progressive films? 

Why are they the most suitable, and who is the least suitable to use juvenile myopia control progressive films? 

Is the research paper on progressive film for juvenile myopia control reliable 

Bring so many problems, let me slowly for you to analyze.

In order to better understand the function of juvenile myopia control progressive film, we must first learn some basic knowledge of eyes. 

One is the triple movement of the eye; 

Second, the significance of AC / a ratio; 

Third, the relationship between eye position and stereopsis; 

The fourth is the adjustment of amplitude and positive and negative relativity.

1) The triple movement of the eye, that is, the three movements brought by the eye when the human eye is looking close, "regulation → accommondation → pupil retraction". A more detailed statement is: when the eye is close, first adjust the lens to increase the refractive power, set the eyes to form the binocular monocular function, and narrow the pupil to adjust the focal depth. In order to better let the focus image on the retina, the degree of focal depth affects the intensity of adjustment and the size of pupil retraction. This process is the three linkage of human vision. The three linkage ensures good near vision function and binocular single vision function. The human eye carries out a series of cooperative actions to ensure that the near object can be seen clearly and quickly. If one of the three movements is affected or changed, the near vision function of human eyes will be seriously affected. For example, if there is insufficient collection, there is no binocular single vision function, there is no stereopsis, and it is impossible to see near for a long time; If the adjustment is insufficient and the nearby objects cannot be seen clearly, visual fatigue will easily occur.

So, after controlling the progressive use of the myopia, the adjustment power will be reduced, but the combination will not decrease. The pupillary changes will not change. The focal depth will be changed, so a good triple movement will lose balance. The long-term use of juvenile myopia to control progressive films will cause a decrease in the regulation power, thereby reducing the amplitude of adjustment. Then it will lead to the visual function problem of insufficient regulation（ Here I would also like to talk about the combined prism, which reduces the adjustment and collection at the same time, but it will be addictive if used for a long time. The adjustment function and collection function of the eyes will be changed, and the amount of positive and negative relative adjustment will also be changed. Here I reserve my opinion on the prevention and treatment of myopia with prism and positive mirror, and there will be a special topic in the future.)

2) The meaning of AC / a ratio is that the adjustment force used when the human eye looks close will bring a corresponding amount of collective force. For our normal eyes, generally, every 1D adjustment force will bring a collection of 4 △ so that the human eye can maintain lasting and comfortable when looking close. If the adjustment function changes and the set remains unchanged, the eye will use the internal rectus muscle to make too much force to produce the set. If this goes on for a long time, it will lead to excessive near collection of eyes. When the collection is excessive, because the extraocular rectus muscle is elongated and excessively compresses the temporal side wall of the eye, the eye is pressed more flat and long, so that the eye axis will also become longer and the degree of myopia will deepen.

After using the juvenile myopia control progressive film, those with normal AC / a ratio, as I said above, did not reduce the development of myopia, but relaxed the adjustment and did not relax the collective force; If those people with low AC / a ratio use it, it will be more serious. Originally, there are few sets brought by adjustment, but now they relax the adjustment. That set depends entirely on the eye fusion image reserve to attract the internal rectus muscle set. Such people can't see close for a long time, and will slowly make the eyes give up the binocular monocular function, so the stereo vision will disappear, resulting in the occurrence of exotropia; People with high AC / a ratio use juvenile myopia control progressive film, which is more suitable for wearing. Because of the high AC / a ratio, the adjustment leads to too many collections. Relax the adjustment, which can reduce the collection and make the eyes more comfortable. However, people with high AC / a ratio account for a small proportion of adolescent myopia, less than 10%.

3)  The relationship between eye position and stereopsis. Most of our normal people's distant eye positions are in exophoric strabismus. At present, the normal eye positions are: Bo 1 △; Within Bi 3 △ this is considered to be the orthographic position. In near vision, the eye position is generally at BI 4 △± 2 △. In order to ensure the normal stereopsis of far and near vision, and lasting and comfortable, the eye position should be within these expected values.

The use of juvenile myopia control progressive film for people with normal eye position has no serious adverse consequences; However, for people with a large amount of exophoria, the consequences of using juvenile myopia control progressive tablets without prism prescription are very serious. If a person with exophoric oblique myopia requires foot correction or overcorrection, but if it is equipped with a progressive film, after the adjustment is relaxed, the collection of near vision is not enough. It is impossible to perform binocular monocular function, which will cause exotropia, which is a fatal problem. For those with implicit oblique myopia, this kind of person is suitable to wear juvenile myopia control progressive film.

4)  Adjustment amplitude and positive and negative relative adjustment. General formula: 18-0.33 × Age = adjustment range. The adjustment range is related to age. At the age of 10, the adjustment range is as high as 14d, and then decreases slowly. When the eyes are short-sighted, wearing glasses or not, the adjustment force used is lower than that used by normal eyes, and it is more obvious not to wear glasses. If you don't wear myopia glasses for a long time, the adjustment force is rarely or almost not used, and only collection is used. Then, such a person's normal adjustment ability will decline, and the adjustment range is much lower than that of his peers. When we correct their myopia, we will find that it is very difficult for them to see near with myopia glasses, which is the visual problem of insufficient adjustment. Positive and negative relative adjustment refers to the degree of relaxation, adjustment and tension of the eyes within a certain distance. The two degrees should be the same, so that the eyes can be comfortable and lasting. If one party is greater than the other, then regulatory problems will occur, such as the decrease of adjustment flexibility and the fuzzy time band at the moment of near or far vision.

After using the juvenile myopia control progressive film, the adjustment is relaxed for a long time, and the adjustment range is reduced. Finally, the adjustment force used by a healthy visual person for near vision is lost. In the long run, MC wearers will rely more on relaxation and regulation, and finally produce visual problems of insufficient regulation, which will lead to the inability of regulation to last. An unprofessional metaphor is that young people get presbyopia; For those with normal positive and negative relative adjustment, juvenile myopia control progressive film is used, because it is an artificial relaxation adjustment, which changes the middle position of positive and negative relative adjustment when the eyes are near.

To sum up, not every child can wear progressive films for juvenile myopia control. From the perspective of normal visual function, most teenagers are not suitable for progressive films. However, in order to pursue higher profits, manufacturers and stores ignore or do not understand the problem of visual function, which will affect the visual function of more teenagers.

I can say that most customers wearing juvenile myopia control progressive films will deepen their myopia, because the lens does not change the customer's eye habits and posture, and the relaxation and adjustment of the lens will also bring new visual problems and cause visual fatigue, but are side effects. Due to the design of progressive film, customers with astigmatism have more problems, and the left and right deformation areas will be more obvious, which will bring more visual fatigue and make the eyes more likely to deepen.

If the juvenile is exophoric strabismus (most myopia customers are exophoric strabismus) and the juvenile myopia control progressive film is used, the visual problem will be expanded. Because it is exophoric strabismus, the adjustment is relaxed and the internal force is reduced, so that the eyes slowly change from recessive to explicit strabismus, damaging the stereoscopic vision function of the eyes. Without stereo vision, there is no sense of space and distance, that is, it destroys the image fusion function of the eye.