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Poor quality glasses may cause astigmatism

Experts warn that poor quality glasses may cause astigmatism. Poor quality glasses bring great harm to people. It will affect astigmatism axis position, bridge of nose development and treatment effect of amblyopia for children, affect the progress of myopia for teenagers, and affect appearance and cause visual fatigue for adults.

Professor Zeng Junwen, director of the optometry center of the affiliated ophthalmic hospital of Sun Yat sen University, said that glasses have become an indispensable part of many people's lives. At present, the glasses market has a certain scale, but it has not been fully standardized. There are still many inferior glasses sold to consumers. So consumers must be careful when choosing glasses. '

Generally speaking, inferior glasses are produced by underground factories without a license. The equipment is simple and the cost is very low, so the price is very low. He pointed out that in terms of lens materials, the resin matrix of inferior glasses is impure, which can cause visual distortion or vertigo. It is easy to cause visual fatigue due to large dispersion effect. There are bad internal stress, poor impact resistance and fragile. The light transmittance is low and the light distribution is uneven. The refractive index is not up to its propaganda standard, exaggerating the ultra-thin degree of the lens. In addition, it can not prevent ultraviolet rays or only a small amount of ultraviolet rays.

At the same time, in the lens surface treatment, poor quality surface treatment, no hard anti flower function. The coating technology is poor and easy to remove. The film can not meet the requirements, low antireflection ability, no waterproof, antifouling, antifogging and other special functions.

In terms of frame materials, inferior glasses have poor metal smelting process, low purity, many impurities, and may even contain radioactive elements harmful to the head, with a large proportion and strong pressure on the bridge of nose, which is not conducive to the development of the bridge of nose of teenagers and children. Poor elasticity, brittle and easy to fracture. Poor surface luster and color, poor corrosion resistance, easy to rust, easy to change color. In addition, there are also skin irritation, allergy, soft, easy deformation and so on.

For the frame processing technology, he also pointed out that the surface of inferior glasses is rough and uneven, and the color is gray. The electroplating technology is poor and easy to decolorize. The electric welding technology is poor, the welding spot is not firm, easy to desolder. Hinges and threads are easily damaged.

Poor quality glasses in the assembly can not meet the national quality standards. The optical center of binocular lens is one high and one low, left or right, pupil distance is not accurate, astigmatism axis is not accurate and so on, which will cause improper prism effect and affect the normal visual function.

After reading the above content, you should have some understanding of the problem that poor quality glasses may induce astigmatism. Today we will introduce here. More topics about eye health will be introduced in the following chapters. Welcome to check. Wish you a happy life!