What are the types of myopia? What is myopia and its classification

The classification of myopia is complex.

According to the degree of myopia: low (mild) myopia, moderate myopia, high myopia, severe myopia.

According to the refractive component: refractive myopia (curvature myopia, refractive index myopia, accommodative myopia), axial myopia.

According to the course of the disease and pathological changes, it is divided into: simple myopia, pathological myopia.

Other types of myopia: traumatic myopia, toxic myopia, drug-induced myopia, diabetic myopia, instrumental myopia, nocturnal myopia, hysterical myopia.

This is based on the classification of optometric technology textbooks, and the classification of some monographs on myopia will be slightly different!

Myopia eyes are divided according to the degree of myopia: mild myopia: less than 300 degrees, moderate myopia: 300-600 degrees, and high myopia: more than 600 degrees.

According to the nature of the lesion, simple myopia eye: generally less than 600 degrees, pathological myopia eye: progressive, with fundus changes.

According to the refractive component: curvature myopia: due to the near-strong curvature of the cornea or lens surface; Refractive myopia:

Caused by the high refractive index of the refractive medium; Axial myopia: It is caused by the excessive development of the anterior-posterior axis of the eye, and most myopic eyes are axial myopia.

According to dynamic refraction: true myopia is still myopic in the case of static refraction, the vast majority of myopic eyes are true myopia, and most of the myopia has a refractive range of 600 degrees.

What is myopia and classification, due to work or playing mobile phones for a long time, many people use their eyes excessively, so that they have myopia problems, and now myopia can be said to be a very basic eye disease, so what is myopia and classification, the following is the relevant content I have collated.

Definition of myopia

To put it simply, the eye can only see clearly when looking near, blurry when looking far, the reason for myopia is because of long-term near objects, so that the muscles and organs (ciliary muscles, lens) that are focused inside the eyeball are accustomed to the focal length of the near view, and when you want to see far, you can't adjust to the focal length of the far (the focus can't fall on the retina) and then slowly form myopia, and myopia is divided into the following pseudomyopia and true myopia.

Classification of myopia

1. Pseudomyopia (refractive myopia).

The cause of pseudomyopia is as mentioned above, because the eye looks at near objects for a long time and causes muscle spasm, so that the ciliary muscle and lens cannot automatically focus (the focus does not fall correctly on the retina behind the eyeball), and it often occurs when children overuse their eyes and have eye fatigue, such as watching TV and mobile phones for too long, which is usually myopia'If the precursor is not well controlled during this period, it will form the following true myopia.

2. True myopia (axial myopia).

The definition of true myopia is that the shape of the eye has changed, the most common situation is that when the child is developing with pseudomyopia, and the eyeball is also growing, so that the ciliary muscle that has spasm can not focus to keep up with the slowly growing eyeball, and finally becomes a vicious circle of eye deformation and deepening of the degree, and once true myopia occurs, due to the change in the shape of the eyeball, it is easy to cause various eye diseases, such as glaucoma, cataract, etc., and more studies have pointed out that more than six people with high myopia, The chance of retinal detachment is more than 40 times that of the average person, and even if you have myopia surgery when you grow up, it is only for the cornea, and it will not help for the deformation of the eyeball, so when parents find that their children have blurred vision, they should correct and control the degree as soon as possible, and try not to become highly myopia.

Myopia is a condition in which parallel rays of light are refracted by the refractive system of the eye in a relaxed state of accommodation, and the focus falls in front of the retina. See near clearly, see far away clearly.

Classification of myopia

1. According to the degree of myopia

Those within this are called mild myopia.

He is moderately myopic.

The above is pathological myopia in high myopia.

2. According to the refractive composition

Axial myopia is caused by excessive development of the anterior-posterior axis of the eye.

Curvature myopia is caused by excessive curvature of the cornea or lens surface.

Refractive myopia is caused by an excessively high refractive interstitial refractive rate.

3. Pseudomyopia, also known as accommodative myopia, is caused by the failure to relax the accommodation when looking at a distance, which is essentially different from the true myopia with refractive components.

No matter what kind of myopia, before the age of 18 is the development period, once myopia is in time**. Experts recommend oral Leyan Vision Nutrients, two packs a day, insist on taking it for a period of time, and cooperate with the correction of bad eye habits, the degree of myopia will be reduced, and the vision will be improved.

So far, myopia has been classified in a variety of ways, many differences, it is still difficult to unify, and the current price is common according to the refractive component, according to the nature of myopia and according to the three classification methods of moderating factors.

Classified according to refractive composition.

1.Axial myopia: caused by an excessively long eye axis.

2.Curvature myopia: caused by increased curvature of the cornea and lens.

3.Exponential myopia: caused by a high refractive index of a refractive medium.

Classified according to the nature of myopia:

1.Simple myopia: There is a relationship between genetics and environment in the cause of the disease.

2.Degenerative myopia: This disease is mainly caused by genetic factors, followed by environmental factors.

3.Secondary myopia: refers to those caused by other eye diseases and systemic diseases, such as diabetes.

Classification according to whether there are moderating factors involved:

1.Pseudomyopia: It is temporary myopia caused by spasm after fatigue of the ciliary muscle.

2.True myopia: It is the so-called myopia, which is not caused by fatigue.

3.Intermediate myopia: that is, both fatigue myopia and substantial myopia.

What are the classification methods and criteria for myopia?

1.Classified according to the degree of myopia.

Low-grade myopia: myopia less than 300 degrees.

Moderate myopia: The degree of myopia is 300 degrees to 600 degrees.

High myopia: myopia greater than 600 degrees.

2.Classified according to refractive composition.

Axial myopia, caused by an eye axis that exceeds the normal range.

Refractive myopia, caused by a refractive power of the cornea or lens that exceeds the normal range.

3.Classification is based on whether pathological changes occur in the eye.

Simple myopia, the degree is mostly within the range, and there is generally no change in the pathology of the fundus.

Pathological myopia: pathological changes in the fundus of varying degrees due to the continuous growth of the eye axis.

1. Classification according to refractive characteristics: curvature myopia, axial myopia, exponential myopia and positional myopia. Curvy myopia is caused by excessive curvature of the cornea or lens surface; Axial myopia is caused by excessive development of the anterior and posterior axes of the eye; Exponential myopia is caused by an excessively high refractive media index; Positional myopia is caused by the anterior position of a refractive medium (usually the lens) in the eyeball, which is less common.

2. Classification according to the degree of myopia: low myopia or mild myopia, moderate myopia and high myopia. Low myopia or mild myopia:

Those with diopters less than or equal to -300 degrees; Moderate myopia: myopia with a diopter between -300 and 600 degrees; High myopia: those with a diopter higher than -600 degrees.

3. According to the progression of the disease course and whether there are pathological changes, it is classified: simple myopia and degenerative myopia. Simple myopia is general myopia, and the refractive power is usually below 600 degrees for low- to moderate myopia, and the progressive development of myopia is slow.

The tissues of the eyeball are normal, and no pathological changes appear; Degenerative myopia, also known as high myopia, is also known as pathological myopia, with a refractive power of more than 600 degrees and a height of up to 4000 degrees. Generally, the onset is early, the axial diameter of the eyeball continues to lengthen, and a series of pathological changes can occur in many tissues of the eyeball.

4. Classification according to the amount of mediation involved: pseudomyopia, true myopia and mixed myopia. Pseudomyopia completely disappears the refraction of myopia after mydriasis, which is manifested as emmetropia or hyperopia.

Patients with true myopia have poor distance vision and good near vision. Mixed myopia is a state of true and false myopia at the same time, and most of the adolescent myopia students are in this state of myopia in the process of heavy learning tasks and physical development.

Baoding Xinshi Eye Hospital.

There are many classification methods for myopia, due to the different understanding of myopia, emphasizing different angles or considering from the perspective of different needs, there are many differences, and it is difficult to unify, the following mainly introduces several domestic classification methods. 1. According to the degree of myopia, it is divided into: mild; Degree; The above is the height.

2. According to the refractive components of myopic eyes: curvature myopia is caused by excessive curvature of the cornea or lens surface; Exponential myopia is caused by a high refractive index of the refractive medium. This type of myopia is collectively known as tortuous myopia.

3. According to the presence or absence of pathological changes, it is divided into: simple myopia, the vast majority of fundus has no changes, and the distance vision can be corrected to normal with appropriate myopia lenses; Pathological myopia, or the eyeball is still growing and has pathological changes after a few years, correction with lenses is often not ideal. 4. According to whether there is a regulatory effect, it is divided into:

pseudomyopia; true myopia; Mixed myopia. (1) pseudomyopia: (2) true myopia; (3) True myopia with pseudo-components (mixed myopia, intermediate myopia, semi-true myopia).

5. According to the form, it is divided into; Myopia; myopic astigmatism, including simple myopic astigmatism, recurrent myopic astigmatism; Myopic anisometropia, including isolated myopic anisometropia and refolding anisometropia. 6. According to the degree, it is divided into: low myopia, moderate myopia, high myopia, and severe myopia.

7. According to the nature, it is divided into primary myopia: congenital myopia, acquired myopia (simple myopia), developmental myopia (adolescent myopia), and adult myopia (late-onset myopia). Symptomatic myopia:

Pseudomyopia: transient accommodative spasms due to hyperopia, astigmatism, or anisometropia. Secondary myopia:

Progressive ocular lesions caused by systemic diseases or other eye diseases, manifested by myopic refractive syndrome, are a type of pathological myopic eyes, which are acquired. Concurrent myopia: transient myopia caused by poisoning, trauma, metabolic abnormalities, environmental changes, and systemic or local diseases.

It is mainly caused by the increase of refractive power due to changes in refractive index or abnormal accommodation, which is seen in toxic myopia, drug-induced myopia, traumatic myopia, diabetic myopia, and early cataract myopia.

Opinions and suggestions: myopia eyes are divided according to the degree of myopia: mild myopia:

Less than 300 degrees, moderate myopia: 300-600 degrees, high myopia: more than 600 degrees.

According to the nature of the lesion, it is divided into: simple myopic eye: generally less than 600 degrees, pathological myopic eye:

Progressive, with fundus changes. According to the refractive component: curvature myopia:

due to near-strong curvature of the corneal or lens surface; Refractive myopia: caused by too high refractive index of the refractive medium; Axial myopia: It is caused by the excessive development of the anterior-posterior axis of the eye, and most myopic eyes are axial myopia.

Myopia can be divided into axial myopia, curvature myopia, refractive index myopia and positional myopia according to their refractive characteristics.

According to the degree of myopia, it can be divided into low myopia or mild myopia (below 300 degrees), moderate myopia (300 degrees to 600 degrees) and high myopia (above 600 degrees).

According to the progression of the disease and the presence or absence of pathological changes, it can be divided into simple myopia and degenerative myopia.

According to the amount of mediation involved, it is divided into pseudomyopia, true myopia and mixed myopia.

You can go to a professional eye hospital for an examination for the specific situation.

Hello is divided into three categories:

1. Classification according to myopia.

Low-grade myopia: myopia less than 300 degrees.

Moderate myopia: The degree of myopia is 300-600 degrees.

High myopia: myopia greater than 600 degrees.

2. Classification according to refractive components:

Axial myopia: The axial length of the eye exceeds the normal range, before the external parallel light enters the eye to focus the retina.

Refractive myopia: the axial length of the eye is normal or basically within the normal range, mostly due to the excessive curvature of the cornea or lens, the refractive power exceeds the normal range, so that the external parallel light enters the eye before focusing the retina.

3. Classification according to whether pathological changes occur in the eye:

Simple myopia: the degree of myopia is within 600 degrees, and there are no pathological changes in the fundus.

Pathological myopia: the axis of the eye continues to grow, and pathological changes in the fundus of varying degrees appear.

1. Classification according to the degree of myopia:

Mild myopia: <300 degrees.

Moderate myopia: 300 600 degrees.

High myopia: >600 degrees.

2. Classification according to whether there is a regulatory role.

Pseudomyopia: also known as accommodative myopia, it is generally the over-adjustment of the lens, and the refraction of myopia completely disappears after pupil dilation, which is manifested as emmetropia or farsightedness.

True myopia: also known as axial myopia, the anteroposterior diameter of the eye axis is extended, and distant light rays enter the eye and are imaged in front of the retina.

Mixed myopia: a condition in which true and false myopia coexist. Myopia has a greater decrease in refraction after mydriasis, but it is still myopia.

Hello, according to the degree of myopia, it is divided into.

1. Mild myopia: no more than 300 degrees, 2. Moderate myopia: 300 600 degrees, 3. High myopia: more than 600 degrees.

It is divided according to whether there is a regulatory effect.

1 True myopia: also known as axial myopia, is due to the growth of the eye axis leading to the formation of myopia in front of the retina 2 pseudomyopia: also known as accommodative myopia, generally the lens is over-adjusted, and the myopia degree completely disappears after the pupil is dilated, and it becomes an emmetropic eye or a farsighted eye.

3. Mixed myopia: the state of true and false myopia at the same time, the myopia degree will be reduced but will not disappear completely after pupil dilation, and there are still some myopia degrees.