How to distinguish true and false myopia?

Abstract: true myopia can be divided into two kinds. One is common axial myopia, that is, the axis of the eye becomes longer and the parallel lines naturally converge in front of the retina; The other is refractive myopia. The eye axis is not long, but there is still myopia in the state of complete paralysis of ciliary muscle. It may be that the lens has been used to such a strong refraction function.

according to data, there are 1.4 billion people suffering from myopia in the world, which is expected to increase to 2.5 billion by 2020. The proportion of myopia in mainland China accounts for 47% of the total population; Higher in Hong Kong and Taiwan, 56%; There are also many in the United States, accounting for 42%; Japan accounts for 46%; Singapore is as high as 59%.

myopia

normal conditions are as follows: when distant parallel light enters the eye, the ciliary muscle of the eye does not need to be adjusted, and the lens is relatively flat, which can refract and focus the light on the retina to form a clear image; When looking at the near object, the light is relatively divergent. At this time, the ciliary muscle is tense and contracted, and the crystal becomes more convex and has stronger diopter. It can still focus the divergent light refraction on the retina, and the image is still clear.

pseudomyopia

when looking at near objects for a long time, it will form ciliary muscle tension or even spasm, and the crystal cannot flatten. At this time, when looking at the distance, the parallel lines from the distance will be imaged in front of the retina due to excessive refraction, resulting in unclear imaging.

at this time, normal vision can be restored by resting or using ciliary muscle paralysis (mydriasis). Myopia at this time is generally referred to as pseudomyopia.

but if bad habits continue to develop, pseudomyopia will also be transformed into true myopia.

true myopia

True myopia can be divided into two types. One is common axial myopia, that is, the axis of the eye becomes longer, and the parallel lines naturally converge in front of the retina; The other is refractive myopia. The eye axis is not long, but there is still myopia in the state of complete paralysis of ciliary muscle. It may be that the lens has been used to such a strong refraction function.

the first symptom of myopia

is to make the corneal surface a little flat and reduce the diopter. Therefore, many people will pull the corners of their eyes, rub their eyes, press their eyes with their hands or eyelids, and overcome the excessive convex lens by flattening the refractive medium. The second method of

and

is to reduce the light entering area of the pupil and increase the depth of field. Everyone who has studied photography knows that reducing the aperture can increase the depth of field and make the image clearer. Therefore, once they want to start myopia, many people will unconsciously squint and frown when looking at things, so they can see things a little clearer.