Relationship between visual acuity, diopter and glasses

Abstract: “refraction” generally refers to the change of the optical path of parallel light. For the eyes, the most direct refractive change is reflected in the bending degree of cornea and lens. The closer you see, The greater the curvature (thickness) of the lens, the greater the adjustment force required, and the more laborious it is. The first self feeling is eye fatigue, that is, the symptom of too long reading close;

Parents who can ask these questions are very rational. We do not advocate that once a child has a vision problem, the first purpose is to take some treatment means. Instead, parents need to fully understand the occurrence and development of myopia and the relationship between related things, so as to help children take correct, reasonable, scientific and easy methods to jointly resist myopia and rationally choose products and vision protection methods.

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some parents are at a loss when they find that their children have vision problems and blindly follow the crowd. As a result, they choose vision correction methods that are not suitable for their children, but play a negative factor. So here is a brief overview of the relationship between the three often asked by parents, hoping to be helpful to parents.

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first say “eyesight”. In short, it means people’s ability to see things clearly. The quality of eyesight is judged by the distance of seeing things clearly. The good ones are 1.5 and 2.0, and the poor ones are 0.1, immediate discrimination and light perception (that is, they can’t see things clearly and can only feel the existence of light). There are many factors affecting vision. Ocular inflammation can cause vision loss (trachoma, red eye disease, etc.); Trauma can also cause vision loss; Lens opacity, vitreous opacity, retinopathy and other diseases can also cause the decline of vision; We have said that myopia, hyperopia and amblyopia are often called visual diseases on the premise of low vision. As long as a person’s vision is normal, no matter whether his refraction is myopia or hyperopia, he can’t be said to be myopia, hyperopia or amblyopia. For example, vision 1.0 The degree is -2.00ds (+ 2.00ds). The visual acuity decline of most young students is mostly related to fatigue caused by close eye use, mostly due to accommodation disorder (regulatory myopia) and eventually organic diseases, that is, the anterior and posterior diameter of the eyeball has changed (i.e. axial myopia).

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and “refraction” generally refer to the change of the optical path of parallel light. For the eyes, the most direct refractive change is reflected in the bending degree of cornea and lens. The closer you see, Curvature of lens The greater the (thickness), the greater the adjustment force required, and the more laborious it is. The first self feeling is eye fatigue, that is, the symptom of reading too long from a close distance; the lens is the most direct adjustment structure for the human eye to see far and near, which is equivalent to a convex lens. It can adjust its bending degree according to its own needs to change the distance of the focus to achieve the purpose of seeing the object of

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vision often refer to the ability of our fundus retina imaging; Diopter refers to the power of the whole refractive system of the eye (cornea, aqueous humor, lens, vitreous) is usually expressed by the degree of the eye. Generally, 1.0 of the visual acuity chart at a distance of 5 meters is the minimum degree requirement, and the degree is only an indicator of the specific curvature of a state specified for people to see the visual object. If the position is changed, there will be different requirements and values, such as the visual object at a distance of 5 meters and the visual object at a distance of 3 meters Degrees are different. Therefore, glasses do not need to be worn all the time. They only supplement the refractive power needed by people to see the things they can’t see clearly.

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people’s original intention of matching glasses is often to see the distant visual objects (blackboard, faces of people coming opposite, vehicles coming in front, etc.), and the purpose of optometry matching glasses is to solve the problem of looking far away. Therefore, there is a principle of matching glasses, that is, it is based on the minimum degree of 1.0 visual acuity chart at 5m, which is not suitable for looking at objects near.

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glasses should be worn selectively, but doctors have to tell myopic patients to wear them often. Imagine the results of wearing them all the time: first, give up self-regulation, because there is no need for self-regulation; Second, myopia is that you can’t see far clearly and see near clearly. You can see near without glasses, but myopic patients mistakenly wear myopia glasses used to see far, which undoubtedly adds an additional adjustment load to the ocular muscles, which is equivalent to adjusting far to near. This is why people often ask, doctors say that glasses can control the degree development, why do glasses wear thicker and thicker?

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are very simple. Ophthalmologists ignore one of the most basic facts: glasses are only a means of correcting vision, not a means of treatment, which is not conducive to the improvement of their naked vision. They mistakenly regard a plan of rights and interests as an invariable truth and a panacea. To put it more directly, myopia glasses are nothing more than to see the visual object about 5 meters away. Everything else is good for nothing. People can be rational on presbyopia glasses: a little observation will find that presbyopias often wear glasses only when they see close, and remove them after reading, because presbyopia doesn’t need glasses to see far, and if they wear them all the time, it will only increase the adjustment discomfort of looking far. However, the wrong wearing of myopia glasses is due to the ignorance and thoughtlessness of our ophthalmologists at first, and then the malicious misleading of some doctors. Why do

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glasses wear deeper and deeper?

myopia glasses are only a vision correction tool, not a treatment. Its only effect is to improve the corrected vision of wearing glasses, which has no effect on the improvement of naked eye vision. At the same time, it has contributed to the accelerated decline of naked eye vision. Wearing myopia glasses, far vision is improved, but the self-regulation function of people’s ocular muscles is also abandoned, and the stalemate of ocular muscles has not been effectively alleviated. When glasses are also worn when looking close, it adds an additional burden to the eye muscles, and it is more difficult to adjust the distance to look close (including the additional degree of glasses). In this way, the refractive adjustment of the eyes is additionally increased than that without glasses. Therefore, it has caused the accelerated decline of vision and the rapid development of eye power. This is the main reason why the more glasses are worn, the deeper they are.