Why do glasses become goldfish eyes after wearing them for a long time? Glasses: This pot I don't carry!

Have you ever heard such a saying: the glasses are worn more, the eyes will be convex, commonly known as goldfish eyes.

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When going to school, many students in order to avoid bulging eyes, often myopia and try not to wear glasses, until they really can't see the blackboard, they will wear it for a while in class, and then take it off after class, so as to avoid wearing glasses for a long time to deform their eyes.

Is this the right thing to do?

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How to say, if the glasses know that they have such a big pot on their backs, it is estimated that they will lift the desk.

Why the eyeballs bulge, we have to start from the beginning.

As we all know, the human eye is like a camera, with parallel rays entering from the aperture (pupil), refracted through the lens (cornea and lens), and finally focused on the negative (retina) to form a clear image.

Myopia, on the other hand, is a problem in some link in the middle, resulting in blurring where we look farther.

Most myopia is axial myopia [1], that is, because the length of the eyeball (axis) exceeds its normal value, it develops from an approximate circle toward an oval.

The cornea and lens can not be adjusted, and the distant parallel light is focused on the retina, and the world in the eye is naturally unclear.

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In general, the normal eye axis length in adults is 23.5 mm to 24 mm, beyond the normal range, and for every 1 mm increase, the degree of myopia increases by 300 degrees [2].

The capacity of our orbit is relatively fixed, the eyeball is stored in the orbit, and there are extraocular muscles, orbital lipids and other structures behind it, and the growth space is very limited.

The eyeballs become longer, the eye sockets can't fit, and they will naturally bulge outward!

Therefore, wearing glasses is not the culprit of the bulging eyeballs, the essence is still myopia itself.

In addition, I feel that the bulge of the eyeballs after wearing glasses has a little psychological effect.

After all, glasses are like two concave lenses, and looking at our eyes through the lenses will be smaller than they actually are.

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When I take off my glasses, I naturally feel that my eyes have become larger and more convex, so I threw this pot to the glasses.

Glasses as a professional back pot, in addition to being regarded as the culprit of the bulging eyeballs, there are many parents who care about their children's vision problems have various misunderstandings about it.

For example, many parents believe that wearing glasses will make the degree deeper and deeper, and once they are worn, they cannot be taken off, so they are not willing to give their children glasses.

According to expert experience and clinical observation, children who are sensitive to visual loss and who are no longer able to see clearly need to be corrected for any degree of myopia [3].

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If you think about it, looking at things has been in a vague state for a long time, in order to see the books clearly, children can only get closer and closer, for a long time, how can the degree of myopia not deepen?

Some parents believe that a slightly lower power ratio when dispensing glasses can prevent the growth of myopia.

On the contrary, studies have shown that deliberately less degrees of myopia increase in the degree of myopia when dispensing glasses [4].

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Moreover, once axial myopia occurs, it is irreversible, because after the eye axis becomes longer, it cannot go back, that is to say, the statement that "the degree of true myopia can be restored" is itself wrong.

In daily life, we can only increase the degree not so quickly by wearing glasses correctly and developing good eye habits.

Since most myopia is caused by the elongation of the eye axis, why does the eye axis become longer?

In fact, scholars have been studying this problem for more than a hundred years, proposing various hypotheses and inferences, but there is no definite conclusion yet.

Some studies believe that myopia is related to heredity, and if parents are myopic, their children are more likely to be myopic [5], and high myopia is more heritable [6].

In addition to genetics, it has also been suggested that prolonged close-up use of the eye significantly increases the prevalence of myopia [7].

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It has also been suggested that the prevalence of myopia is also related to factors such as geography, age, and outdoor activities [8].

Can only say... Myopia is like an all-pervasive little goblin, a little careless, will paste a layer of mosaic on our world, not only will affect life, but also affect the appearance.

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What is even more frightening is that after developing high myopia, complications such as amblyopia, glaucoma, cataracts, and retinal detachment may occur, and in severe cases, blindness may even occur [9].

Therefore, we must protect our vision well, and we must remember the "20-20-20 rule" in our daily lives - every 20 minutes of close use of the eyes, looking 20 feet (6 meters) away for 20 seconds.

Read more medical texts: how to prevent myopia?

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Seeing you here, put down your phone and rest your eyes

Review expert: Guo Chungang | Director and Chief Physician of the Department of Ophthalmology, Beijing You'an Hospital, Capital Medical University

bibliography

[1] Meng W , Butterworth J , Malecaze F , et al. Axial length of myopia: a review of current research. [J]. Ophthalmologica, 2011, 225(3):127-134.

Li Yuanyuan, Zhang Xiaofeng. Influencing factors and treatment progress of myopia formation in adolescents and children[J]. International Journal of Ophthalmology, 2018, 18(12):70-73.

Ophthalmology Branch of Chinese Medical Association. Expert consensus on refractive correction in children (2017)[J]. Chinese Journal of Optometry and Vision Science, 2017, 019(012):705-710.

[4] Li S M , Li S Y , Liu L R , et al. Full correction and Undercorrection of Myopia Evaluation Trial: design and baseline data of a randomized, controlled, double-blind trial[J]. Australian & New Zealand Journal of Ophthalmology, 2013, 41(4):329-338.

[5] Landmann A , Bechrakis E . [Nature or nurture : Effects of parental ametropia on children's refractive errors.] [J]. Der Ophthalmologe, 2013, 110(12):1179.

[6] GUGGENHEIM, J. A . The heritability of high myopia: a reanalysis of Goldschmidt's data[J]. Journal of Medical Genetics, 2000, 37(3):227-31.

[7] Bao J , Drobe B , Wang Y , et al. Influence of Near Tasks on Posture in Myopic Chinese Schoolchildren[J]. Optometry & Vision ence Official Publication of the American Academy of Optometry, 2015, 92(8):908-915.

[8] Shi-Ming L , He L , Si-Yuan L , et al. Time Outdoors and Myopia Progression Over 2 Years in Chinese Children: The Anyang Childhood Eye Study[J]. Investigative Ophthalmology & Visual ence, 2015, 56(8):4734-40.

[9] Carr BJ, Stell WK. The Science Behind Myopia. In: Kolb H, Fernandez E, Nelson R, eds. Webvision: The Organization of the Retina and Visual System. Salt Lake City (UT): University of Utah Health Sciences Center; November 7, 2017.

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