Axial myopia

Most myopia is axial myopia, which means that other refractive components are basically normal, but the eye's "axis length is too long", causing parallel light to focus in front of the retina after entering the eye, forming myopia. The average length of a normal healthy eye axis is about 2.4 cm, and for a 6-year-old child it is about 2.2 cm. During childhood and adolescence, if the eyes are used too much at close range, the eye axis will lengthen quickly. For every 0.1 cm increase in the eye axis, the degree of myopia will increase by 300 degrees. In other words, avoiding "axis length" can effectively prevent myopia from worsening.

Refractive Myopia

The axial length of the eye is within the normal range, but because the ciliary muscle cannot relax to adjust the "cornea or lens" to the required thickness and curvature, the light is refracted excessively after entering the eye, and the image is focused in front of the retina, forming myopia.

In the early stages of refractive myopia, "pseudomyopia" will form. This is mainly caused by long-term close-up use of the eyes, which will cause the ciliary muscles to be in a spasm and unable to relax. At this time, the eye test will show a false impression of "myopia" with a certain degree, which is the so-called "pseudomyopia". Give your eyes more rest or use mydriatic drugs, and pseudomyopia can usually return to normal. However, if pseudomyopia is not relieved, it will turn into true myopia after a long time.

Myopia is composed of a large part of axial myopia (which cannot be improved) and a small part of refractive myopia (which can be relaxed). However, when looking at close objects for a long time, the pressure of refractive myopia will be transformed into axial length growth of axial myopia. The two are in a vicious cycle, resulting in the continuous deepening of myopia.