Myopia has become a very serious health problem in China. Statistics show that the overall myopia rate of children and adolescents in China will be 52.7% in 2021.
The most common way to correct vision is to wear glasses (including contact lenses). Contact lenses include corneal contact lenses, corneal plastic lenses and scleral lenses. So what are the differences between different glasses and how to classify them? Let's have a look!
（1） Frame glasses
Classification suggestion: 90049090
Lens frames and lens frame parts are classified in item 9003, glass lenses that are not optically processed are classified in item 7015, glass lenses that are optically processed are classified in item 9001, and non glass lenses that constitute optical elements are classified in item 9001.
（2） Corneal contact lens
Corneal contact lens, the most common contact lens, is a kind of lens that is worn on the cornea of the eyeball to correct vision or protect the eyes. According to the hardness of the material, it includes hard, semi-hard and soft. Its principle is to make the object image appear on the retina through the refraction of light by the lens, to a certain extent, replacing the zoom function of the eyeball, and achieving the effect of clearly presenting objects at different distances on the retina. Contact lenses not only bring great improvement to myopia, hyperopia, astigmatism and other ametropic patients in terms of appearance and convenience, but also have a wide field of vision and realistic vision. In addition, it has also played a special role in controlling the development of juvenile myopia and astigmatism and treating special eye diseases.
Classification suggestion: 90013000
（3） Keratoscope
Corneal plastic lens originated in the United States. After 50 years of development, it has been applied in 34 countries around the world. The high oxygen permeable rigid contact lenses worn on the cornea of the eyeball can temporarily correct the vision of the wearer through special design. Corneal shaping lens is a kind of high permeability oxygen lens with multi arc segment special design on the inner surface. After wearing for a certain time, it can flatten the central shape of the cornea and temporarily reduce the myopia through the physical principle that the tear between the lens and the cornea forms a hydraulic pressure. Corneal plastic lens can not only correct myopia, but also slow down the growth of myopia. However, the above corneal contact lens can only correct myopia and cannot control the growth of myopia.
Classification suggestion: 90185000.
（4） Scleral mirror
Scleral lens is a special kind of corneal contact lens, also known as scleral rigid oxygen permeable corneal contact lens. It is called scleral mirror because the lens spans the cornea like a bridge, does not contact it, and extends all the way to the sclera (the white part forming the outer ocular wall). Compared with the ordinary corneal contact lens, its diameter is larger than the cornea, and the diameter can range from 14 mm to 20 mm. Scleral lens is suitable for daily wearing under various ocular conditions to solve clinical pain points. For example, improve visual quality, protect cornea and correct vision, which can be used to correct myopia, hyperopia, astigmatism and presbyopia.
Classification suggestion: 90013000
Although wearing glasses can control the development of myopia, astigmatism and other problems, we still hope that everyone can develop good eye habits, do not look at things at close distance for a long time, do not lie down or lie down to read, do not have too strong or weak lighting, maintain a certain outdoor movement, adhere to eye protection exercises, and protect their eyes.
