Below is a pair of metal sunglasses to decorate and protect your eyes.

Glasses evolved gradually from magnifying glasses. As early as the Eastern Han Dynasty, my country had ground crystal optical lenses, which were the prototype of glasses. The earliest glasses in the West appeared in Italy, introduced by Alessandro di Spina of Florence. In 1268, Roger Bacon first recorded lenses for optical purposes; in 1784, American inventor Benjamin Franklin invented dual-purpose glasses for both near and far vision; in 1825, British astronomer George Airy invented glasses that could correct astigmatism; in 1888, the first pair of contact lenses was born.

Below is a pair of ancient glasses.

 

Glasses consist of lenses and frames. According to their uses, they can be divided into 15 types: myopia glasses, hyperopia glasses, reading glasses, astigmatism glasses, plain glasses, computer goggles, goggles, swimming goggles, night vision goggles, e-sports goggles, e-sports goggles, goggles, sunglasses, toy glasses, and sunglasses. There are also special glasses for viewing 3D stereoscopic images or virtual real images. According to the material, there are acetate glasses, metal glasses, titanium glasses, buffalo horn glasses, bamboo glasses, memory metal glasses, etc. Modern glasses usually have a nose pad in the middle of the lens and a soft cushion where the left and right arms rest on the ears. People who love beauty or are not used to wearing glasses can choose to correct their vision with contact lenses.

Below is a pair of acetate glasses with three rivets and bevels.

 

 

Glasses evolved from magnifying glasses. Archaeological findings have confirmed that my country had ground crystal optical lenses, the prototype of glasses, as early as the Eastern Han Dynasty (first century AD). According to Marco Polo, around 1274, he observed that elderly people in Yuan Dadu and other places wore glasses when reading small characters. In the West, Roger Bacon first recorded lenses for optical purposes in 1268. The earliest glasses appeared in Italy, introduced by Alessandro di Spina of Florence. The earliest portrait of glasses, "Hugh of Provence", was painted by Tommaso da Modena in 1352. It is said that it was invented by an optician named Almato and an Italian named Spina who lived in Pisa.

American inventor Benjamin Franklin, who suffered from myopia and hyperopia, invented dual-purpose glasses for myopia and hyperopia in 1784; in 1825, British astronomer George Airy invented glasses that could correct astigmatism. Glasses appeared in China in the middle of the Ming Dynasty. Western glasses were introduced to China through the Western Regions or Southeast Asia in the Ming Dynasty. Tian Yiheng of the Wanli period of the Ming Dynasty wrote in the entry "叆叇" in Volume 2 of "Liu Qing Rizha": "Every time I read an article, my eyesight becomes dull and I cannot distinguish fine writing. I cover my eyes with this, and my mind is not distracted, and the strokes are clear. I use silk to tie it together and tie it behind my head. No one can recognize it, and they raise it to ask me.

 

 

In Chinese history, with the development of individual handicrafts, the materials used for glasses have evolved from natural crystal stones to glass. The scope of use of glasses has begun to be promoted and expanded to the public, and the production technology has also developed in new ways.

Gusu (Suzhou) in China is the birthplace of Chinese glasses. Suzhou not only has a long history of producing glasses, but has also played a great role in promoting the development of China's eyewear industry. In the early years of Chongzhen in the Ming Dynasty (1628 AD), an outstanding technician appeared in the history of Suzhou glasses. His name was Sun Yunqiu, with the courtesy name Wenyu and Sibin, and his native place was Wujiang. He was diligent and studious since he was a child. At that time, he saw that people with poor eyesight were very painful, but "single-view" glasses were inconvenient to use. So he carefully developed a lens that can be often mounted on glasses. After repeated experiments, he invented a lens grinding machine-a traction wheel using mechanical principles. This kind of pull-wheel is the so-called classical processing of water orange. It is turned by pedals, and uses mineral sand, white mud, brick dust and other materials as abrasives or polishing materials to grind the lenses into convex and concave lenses to meet the needs of eye refraction. Finally, he finally mastered the grinding technology and ground lenses with natural crystal stones. At the same time, he mastered the technology of "optical examination" and developed lenses of various types and various light intensities such as presbyopia, myopia, hyperopia, etc. according to people's age and different vision. He also compiled a set of original optometry methods of "matching the eyes with the mirror" to test the eyes and match the environment. In this way, you can match the glasses with the eyes, the effect is not bad at all, and it is more convenient and comfortable to wear on the face to meet the needs of each person's vision. This is the beginning of China's independent optometry and glasses matching.

Later, Sun Yunqiu invented and developed optical lenses for different purposes, including dozens of types such as flower mirrors, mandarin duck mirrors, magnifying glasses, multi-faceted mirrors, and phantom mirrors. From then on, the glasses made by Sun Yunqiu became famous everywhere. Unfortunately, such a talented technician died at the age of 33, but he left behind a scientific work called "Mirror History", which played an immeasurable role in promoting the eyewear manufacturing technology of later generations.

After Sun Yunqiu, during the Qianlong and Jiaqing periods of the Qing Dynasty, Suzhou produced another talent for making glasses, named Chu Sanshan. He further developed the technology of making glasses and had a great influence.

Because Suzhou produced two outstanding technical talents for making glasses, Sun Yunqiu and Chu Sanshan, it promoted the formation and development of the Suzhou eyewear industry at that time. In 1735, Suzhou had already seen workshops specializing in the production of glasses.

During the Kangxi period of the Qing Dynasty, the production and sales of glasses had flourished in Beijing, Shanghai, Suzhou, Tianjin, Guangzhou and other places. Glasses have become a special commodity.

 

 

Since the Opium War in 1840, Western eyewear technology has been introduced into China, opening up a new path for the rise of the eyewear industry. In the late Qing Dynasty, the first British man, John Goddard, opened the "Goddard Foreign Company" in Shanghai, specializing in machine-grinded and optical glasses. Later, other foreigners followed suit. For example, TobiM opened the "Mingjing Foreign Company" and the British Jew Remoton opened the "Remoton Foreign Company".

Since then, in 1911, the Chinese who had worked in the "Golden Foreign Company" raised funds to open the "China Jingyi Optical Company". The opening of the Jingyi Optical Company has brought new development to the Chinese optical industry. In particular, there have been great reforms in optometry and glasses fitting:

1. The "Duiguangpai" optometry and glasses fitting that has been used for a long time in old-style stores has been abolished, and the optometry technology combining subject and object has been adopted.

2. The method of making lenses by pure manual operation has been eliminated, mechanical grinding and processing equipment has been set up, and grinding technology has been developed. At this time, not only lenses of various properties and specifications can be ground, but also various frames (frames) can be supervised by self-made.

3. In terms of inspection, grinding, cutting, installation, correction, and manufacturing technologies, due to the adoption of some new foreign technologies and equipment, a generation of professional talents in making glasses has been cultivated, which has laid a solid foundation for the rapid formation of a new technical team in the Chinese optical industry.

With the rapid development of China's economic construction, the eyewear industry has also been vigorously developed. In terms of industry, major production areas such as Beijing, Shanghai, and Suzhou all have a certain scale of eyewear production base. For example, Shanghai Glasses Factory No. 1, Shanghai Glasses Factory No. 2, Beijing Glasses Factory, Beijing 608 Factory, Beijing 603 Factory, Suzhou Glasses Factory, etc. have become large-scale backbone enterprises in China's eyewear industry, and their scale is nearly 1,000. The number of production personnel, quality and supporting capabilities are all ranked first in the country. Some products are municipal or national quality products, and some famous brand products have been exported for many years and marketed throughout the country, and are well-known at home and abroad.

In addition, some defense industry enterprises and instrumentation industries have also turned to the production and processing of the eyewear industry, and commercial service departments have also continuously expanded or increased sales outlets and added optometry equipment and instruments. Some cities also attach great importance to theoretical education. For example, Beijing, Shanghai, Guangzhou, Tianjin, Chongqing, etc. have also opened short-term training courses for eyewear technology and professional technical schools for employees, which have trained a large number of professional and technical talents for the eyewear industry.

In April 1985, the founding conference of the "China Optical Association" of the national optical industry was held in Danyang City, Jiangsu Province, under the initiative of the Ministry of Light Industry. There were more than 140 collective member enterprises attending the meeting, including 85 large-scale backbone enterprises, which were affiliated to the Ministry of Light Industry, the Ministry of Commerce, the Ministry of Machinery Industry, the Ministry of Ordnance Industry, the Ministry of Agriculture, Animal Husbandry and Fisheries, the Ministry of Health and the State Science and Technology Commission; they were located in 31 cities in 14 provinces, municipalities and autonomous regions; there were 27,237 employees in total. Among them, there were 1,393 technical personnel: 15 units with more than 500 people, 29 units with 200-500 people, and 41 units with less than 200 people. According to the economic nature: 15 state-owned enterprises, 49 collective enterprises, 10 township enterprises, and several Sino-foreign joint ventures. These 85 units have a total net fixed asset value of 145.22 million yuan. In 1984, the annual production capacity was: 20.18 million pairs of frames (including 5.9 million pairs of metal frames), 16.09 million pairs of lenses, and 16.94 million pairs of blanks; the total output value was 140 million yuan, the total sales were 190 million yuan, the total profit was 34.49 million yuan, and the annual export of frames and lenses was 1.5 million pairs, with a foreign exchange of 750,000 US dollars. In the more than one year after the establishment of the Optical Association, nearly 100 factories and merchants applied to join the association. By the end of 1986, it had developed into 240 collective member enterprises with a total of more than 30,000 employees. Shenzhen has become another global center for eyewear manufacturing. In addition to Wenzhou, Zhejiang and Danyang, Jiangsu, China's eyewear industry base, Shenzhen is the center of global high-end eyewear manufacturing and export. Shenzhen has more than 300 eyewear companies, supplying 70% of the international market's eyewear exports. 90% of the major international brands are concentrated in Shenzhen, which has become a designated manufacturing base. There are also a few eyewear companies in other cities in the Pearl River Delta region, such as Guangzhou, Zhongshan and Dongguan, but the current listed companies are mainly concentrated in Shenzhen. Shenzhen's eyewear factories are mainly concentrated in Henggang Town, Longgang District, where more than 100,000 people are engaged in the eyewear industry, making it a veritable super world eyewear factory.

The development of China's eyewear industry has gone through thousands of years of development and change. It has formed a large industry with a certain scale and certain supporting production capacity, becoming an indispensable part of the entire national economy and making due contributions to the country and the people.

A new market has emerged in China's eyewear market: the online market. This is a manifestation of the significant role played by e-commerce in traditional industries. As the world's first comprehensive industry business information collection platform, it brings together information on consignment product exhibitions, agency project investment information, and direct sales product supply information from all walks of life. It has the characteristics of being able to serve dealers, agents, and buyers at the same time. Business Home is the website with the most resources for dealers and agents. Among them, the exhibition bar is more suitable for the exhibition and sale of consignment products, the investment promotion is more suitable for the investment promotion of agency projects, and the supply is more suitable for the wholesale and retail direct sales of products. It has the function of advertising dissemination. Compared with Alibaba and other B2B (B2B refers to the marketing relationship between enterprises), it has more dealers and agents. Compared with search engines such as Baidu, it has rich classified information, strong sales and investment promotion functions, and more dealers and buyers.

In April 2023, researchers at Cornell University in the United States developed a sonar glasses that can continuously identify up to 31 silent commands by tracking the movements of lips and mouths through acoustic sensing and artificial intelligence. The system can provide assistance for those who are temporarily inconvenient to speak or cannot speak. Culture

The culture of glasses fully reflects the cultural characteristics of a country and nation, such as ideology, morality, values, beliefs, customs and habits, and develops with the development of culture in various historical eras. It is manifested in a tangible way by combining material and art. On the one hand, it reflects the progress of social civilization, and at the same time, it also reflects the identity, social status, ideas, interests and hobbies of the wearer.

 

 

The cultural connotation of lenses mainly reflects the quality of the material, the size, curve, combination, color, gloss and other exquisiteness of the lenses. In ancient times, the differences in the glasses used by emperors, officials, wealthy people and ordinary people reflected completely different cultural colors and connotations. In modern times, the glasses used by men and women in various social classes such as workers, farmers, businessmen, scholars, and soldiers have different styles, which all reflect people's ideological and cultural connotations.

Frame culture

Frame culture also reflects the quality of materials, the exquisiteness of the frame's appearance, color, decoration, and the meaning of pictures and texts. In ancient times, frames were often engraved with patterns such as blessing, wealth, longevity, and wealth, reflecting the value connotations of "blessings in front of you", "blessings and longevity", "official career is prosperous", and "making money in all seasons". At the same time, the beams are often engraved with store names, names, names, gold content, etc. Depending on social status and identity, the frames used by emperors and dignitaries were mostly made of precious materials such as gold, silver, tortoise shell, and ivory, while the glasses used by ordinary people were mostly made of copper, iron, steel, and wood. The beam patterns of glasses gradually transitioned from the original arch bridge shape, gate shape, city gate hole shape, and arc shape to the straight shape, bamboo joint shape, and up and down beam shape; the beam clips and side clips transitioned from cloud pattern shape, cat head shape, and tiger head shape to eagle head shape, two-point shape, and plum blossom point shape.

Modern frames have further developed on the basis of ancient frame culture. Whether in form, design, decoration, pattern, or color, they have become more colorful, reflecting new values ​​and aesthetics. [1]

Physical properties

1. Refractive index (n);

2. Water content (% by weight);

3. Oxygen permeability (cm2/s) (mlO2/ml·kPa)@25℃×10-11;

4. Elastic modulus Pa*104;

5. Specific gravity (g/cm3).

Transparency

Refers to the clarity of a substance. It is a comprehensive reflection of the chemistry, purity, hydration and other factors of the substance. The transparency of a substance is usually expressed as the percentage of light of a specific wavelength passing through a sample of the substance. This value is between 92% and 98% in most clear contact lens materials (uncolored).

Hardness and toughness

The hardness of a material is an important quality indicator that reflects the manufacturing and durability of the lens. The hardness property is more closely related to hard lenses than soft lenses. Toughness reflects the degree of flexibility of the material. Lenses made of materials with good flexibility feel good at the initial wear stage, but cannot correct corneal astigmatism because they tend to stick to the cornea and conform to the shape of the cornea.

Tensile strength

Indicates the maximum tensile force that a material can withstand before it breaks in a stretched state. High tensile strength → good durability.

Elastic modulus

1. Indicates the ability of a material to maintain its shape when under pressure.

2. Materials with low elastic modulus → low resistance to pressure.

3. Materials with high elastic modulus → better resistance to pressure, so as to maintain shape and provide better visual effects.

Lens function

In terms of the function of the lens, it has the functions of adjusting the amount of light entering the eye, correcting vision, protecting eye safety and clinically treating eye diseases. Children with strabismus caused by refractive abnormalities and patients with refractive abnormalities accompanied by headaches can be treated by wearing glasses. The function of the glasses frame, in addition to its role as a bracket for the glasses worn on people's eyes, is also cosmetic and decorative. Modern fashionistas emphasize that glasses should be in harmony with the facial makeup and clothing of people of the times, reflecting the symbols of high social class, elegant knowledge, fashion, etc.

Glasses are lenses embedded in a frame and worn in front of the eyes to improve vision, protect the eyes or for decorative purposes. There are also special glasses for viewing 3D stereoscopic images or virtual real images.

Modern glasses usually have a nose pad (nose bridge support) in the middle of the lens, and soft pads where the left and right arms rest on the ears.

Sunglasses

Sunglasses, also known as sunglasses, are designed to protect the eyes. The lenses are often black or dark to prevent the sun (especially ultraviolet rays) from irritating the eyes. Sunglasses were available in China during the Song Dynasty.

Below is a pair of acetate sunglasses.

 

 

The oldest glasses in China are round monocles made of crystal or transparent minerals.

In the Ming Dynasty, Western glasses were introduced to China through the Western Regions or Southeast Asia. Wu Kuan wrote a poem to thank his friend after receiving the glasses as a gift. The description in the poem is "round like a pea, clean like mica", and the usage is "hold it close to the eye socket". Monocles are also called "single lenses", "single lenses already existed in the Ming Dynasty, and it is said to be a Western legacy." ("Suzhou Prefecture Records")

 

 

Many car drivers often wear a pair of black glasses when driving. When driving in the sun or on snowy days, these black glasses can protect the eyes from long-term stimulation of strong light. However, when the car suddenly drives from a bright place to a dark place, wearing black glasses becomes a burden. It is really inconvenient to put them on and take them off. Is there any good way to relieve this trouble for drivers? Yes, wear photochromic glasses. In the sun, it is a pair of black sunglasses, and the dark glass lenses block the dazzling light. In a room with soft light, it becomes the same as ordinary glasses, transparent and colorless.

The secret of photochromic glasses is in the glass. This special glass is called "photochromic" glass. During its manufacturing process, it is pre-mixed with light-sensitive substances such as silver chloride, silver bromide (collectively known as silver halide), etc., as well as a small amount of copper oxide catalyst. The lens changes from no color to light gray and brown, and then from black glasses back to ordinary glasses, all of which are magic tricks of silver halide. In the glass of photochromic glasses, there is a process of change that is very similar to the exposure and imaging of photosensitive film. When silver halide is exposed to light, it decomposes into many black silver particles, which are evenly distributed in the glass. As a result, the glass lens appears dim and blocks the passage of light. This is black glasses. However, unlike the situation on photosensitive film, the silver atoms and halogen atoms generated after the decomposition of silver halide are still tightly together. When returning to a slightly darker place, under the promotion of copper oxide catalyst, silver and halogen recombine to form silver halide, and the glass lens becomes transparent again.

Silver halide resides in the glass, and the decomposition and combination reactions are repeated endlessly. Photographic film and printing paper can only be used once, but photochromic glasses can be used forever. Photochromic glasses can not only darken and brighten with the intensity of light, but also absorb ultraviolet rays that are harmful to human eyes. They are indeed the best glasses. If all window glass is replaced with photochromic glass, on sunny days, sunlight cannot shine into the room; in some high-end hotels and restaurants, photochromic glass has been installed. If the windows of car cabs and tour buses are equipped with this kind of photochromic glass, there is no need to wear photochromic glasses under direct sunlight. The light in the car is always soft, avoiding the glare and exposure to the sun. How happy everyone will be.

 

 

Contact lenses, as the name suggests, are "invisible". They have the function of correcting vision like ordinary glasses and eliminate the inconvenience brought by frame glasses, so wearing contact lenses has become a fashion today. However, contact lenses are not suitable for all people who need glasses. Who should not wear contact lenses?

People with colds often carry a large number of germs on their hands, which can easily enter the eyes when taking and wearing contact lenses. In addition, colds are often accompanied by mild retinal inflammation, and wearing contact lenses will aggravate the inflammation. Many cold, cough and pain medications contain ingredients that inhibit tears. Reduced tear secretion will make contact lenses too dry and less transparent, which will affect vision.

Complications that are prone to occur when wearing contact lenses for people with allergies include mild inflammation, itchy eyes, redness, conjunctivitis and swollen eyes. If these symptoms are not treated for a long time, they may endanger vision. If people with allergies must wear contact lenses, it is best to use them only during the day and stop using them at least one day a week. If inflammation occurs, it is best to stop using them. If the inflammation is not relieved after 2 to 3 days, you should go to the hospital immediately.

Patients with glaucoma, chronic dacryocystitis, conjunctivitis, corneal ulcers, hyperthyroidism and other diseases who have been equipped with contact lenses and whose eyes are in the inflammatory stage should wait until the inflammation disappears before wearing them.

When patients with fever have a fever, the local resistance of the eyes decreases, the secretion of tears decreases, and Bacillus subtilis will multiply in large numbers, causing the metabolites of bacteria to be deposited between the cornea and the lens, resulting in reduced oxygen permeability of the contact lenses and interference with the normal metabolism of the cornea, thus causing bacterial corneal ulcers.

After the age of 40, the eye tissues of middle-aged and elderly people will undergo relatively obvious degenerative changes. The local resistance of the eyes decreases, especially the ability of the eyeball to tolerate hypoxia. At this time, if a thin layer of lenses is worn on the surface of the eyeball, it will cause hypoxia of the eyeball, which is prone to complications such as corneal infection and ulcers. Middle-aged people aged 40 to 60 can wear contact lenses for a short time, and it is best not to wear contact lenses for the elderly over 60 years old, otherwise it is easy to cause serious complications and permanent vision damage.

Pregnant women are not suitable for wearing contact lenses. During pregnancy, due to changes in the body's endocrine function, the barrier function of the corneal tissue decreases, tear secretion decreases, and causes discomfort when wearing glasses, so it is best not to wear them.

 

 

Crystal glasses are expensive, and they make people feel cool after wearing them. Some people think that they can nourish the eyes, which is not scientifically based. Crystal was first used to make glasses because optical glass could not be made at that time, and there was no better optical material than crystal. Crystal glasses are expensive because crystal is hard and brittle, not easy to annihilate, and the output of pure crystal is small. It is not because it has a special maintenance effect on the eyes. People feel cool when wearing crystal glasses because crystal lenses absorb less ultraviolet and infrared rays and have a lower temperature, but they cannot nourish the eyes.

 

 

Have you ever experienced or seen a bloody scene of eye injuries caused by physical collisions or external forces on the sports field? Especially in some highly competitive sports, due to the fierce confrontation between physical bodies and sports equipment, any small negligence and unintentional collision may cause permanent damage to the eyes. Traditional optical glasses cannot really protect the eyes except for compensating for vision. Instead, there are layers of safety hazards. Under the action of external forces, the frames and lenses are very easy to fall off/deform or break (break) and damage the eyes. Eye injuries mainly include: (1) corneal scratches; (2) iris inflammation; (3) anterior eye congestion; (4) traumatic cataracts; (5) retinal swelling; (6) eye corner rupture, etc.

Below is a pair of injection molded sports sunglasses.

 

 

Frame: Designed for myopic basketball enthusiasts, the integrated frame is processed by high-tech technology, and the width and curvature are more suitable for the facial features of Oriental people. The corners are flexible and not easy to deform, which can more effectively protect the eyes and nose bridge. The side wing air holes make it safer and more comfortable to wear, so you can gallop on the sports field without any worries.

Nose pad: The unique, soft, elastic and anti-allergic silicone nose pad prevents the frame from being too close to the face, and can effectively resist and buffer the impact on the eyes when in close contact with the opponent, protecting the eyes from damage.

Suitable for basketball, football, volleyball, tennis, rock climbing, cross-country and other sports.

Self-adjusting myopia glasses

Self-adjusting myopia glasses are based on optical principles and can consciously sense changes in the curvature of the lens and adjust the diopter of the new soft lens accordingly, so that a pair of glasses can be used for a long time without replacement, saving trouble and money, and realizing a major revolution in the application of optics and the history of glasses.

Rearview mirror

A special kind of glasses. It looks the same as ordinary glasses from the front. After wearing it, you can clearly see the situation behind you through the outside of the lens, so that detectives can look ahead and behind conveniently and beware of being tracked. As far as tracking and monitoring are concerned, it can be operated behind the monitored object, in front of it or to the side, with a good concealment effect.

Corrective glasses

Commonly used glasses mainly use lenses, prisms, corneal contact lenses, etc. to correct vision in order to eliminate visual fatigue and protect or treat the eyes. There are many types of glasses, and optical glasses and contact glasses are mainly used to correct refractive errors.

Correction of myopia:

You should wear a concave lens with appropriate focal power, so that the light can be properly diverged through the concave lens, and then refracted by the eyes to form a clear image on the retina.

Correction of hyperopia:

You should wear a convex lens with appropriate focal power, so that the parallel light from a distance can be properly converged through the convex lens, and then refracted by the eyes to form a clear image on the retina.

Correction of astigmatism:

It varies depending on the type of astigmatism. For simple hyperopic astigmatism, a convex cylindrical lens with appropriate degree and a certain axis should be worn; for simple myopic astigmatism, a concave cylindrical lens with appropriate degree and a certain axis should be worn; for compound astigmatism, a convex-convex (or concave-concave) composite cylindrical lens with appropriate degree and axis should be worn; for mixed astigmatism, a convex-concave composite cylindrical lens with appropriate degree and axis should be worn. But no matter which type of astigmatism it is, the axial direction of the cylindrical lens should be strictly measured when wearing glasses, so that the astigmatism can be effectively corrected on the meridian plane that needs to be corrected. For irregular astigmatism, since the refractive power is different on the same meridian plane, it cannot be corrected by cylindrical lenses. Contact lenses (invisible lenses) can be used for correction.

TV glasses

Mainly using virtual reality technology, video glasses project the image of the display screen with a physical size of only 0.24 inches onto the retina of the eyeball, which produces an effect equivalent to the human eye looking at a large screen at a distance of 2 meters.

Functional glasses

Refers to special glasses that can bring certain favorable characteristics to the eyes of specific people in a specific environment and stage, and can change the visual perception and make the vision more comfortable, clear and soft. According to the introduction and classification of functional glasses in relevant domestic and foreign materials, it is believed that functional glasses generally include: student-specific glasses, college students-specific glasses, computer-specific glasses, sports-specific glasses, driving-specific glasses, smart reading glasses, military and police-specific glasses, etc. The largest functional glasses entrepreneur in China is a technology company specializing in the research, development and sales of functional glasses.

Antique glasses

Antique glasses refer to old-fashioned glasses that are handmade and assembled in a single piece. Glasses produced by current mechanical assembly lines are not included.

Glasses are imported products. According to research, the earliest glasses appeared in Italy. The first portrait of a person wearing glasses in history was the Provence portrait made by Tommaso in 1352 in Verviso, which was equivalent to the Hongwu period of the Ming Dynasty in China. According to some data, glasses were introduced to China from the West in the middle of the Ming Dynasty, but they appeared in large numbers in the early Qing Dynasty. Later, the Cantonese imitated their style and made them with crystal stones.

The antique glasses that can be found in the market are mostly products from the 1920s and 1930s. They are characterized by exquisite materials. Gold is the most common raw material. In addition, there are platinum, purple gold, black crystal, tortoise shell, copper, silver, ivory, etc. Whether it is the grinding of the lens to the "bridge" connecting the two lenses, including the temples, pattern carving, etc., all are handmade. This is the same as the early antique clocks. Each piece is a handicraft with fine craftsmanship. [2]

Eyeglass frames

Early on, the main materials used for eyeglass frames were metal and tortoise shell, stainless steel, titanium, nickel silver, plastic, monel, nickel alloy and other materials.

There have also been many breakthroughs in the technology and application of eyeglass frames. Eyeglasses with memory alloy frames can maintain their shape and will not break even if bent, which not only makes the glasses last longer, but also avoids the inconvenience caused by frame breakage. Adding springs to the hinges of the frame arms also makes the glasses more durable.

Eyeglass frames made of titanium are lighter and more corrosion-resistant, preventing them from losing their luster due to corrosion by sweat during long-term wear.

 

 

National standards are divided into mandatory national standards (GB) and recommended national standards (GB/T). The number of national standards consists of the code of the national standard, the serial number of the national standard release and the year of the national standard release (using the last two digits of the release year).

Mandatory national standards are standards that protect human health, personal and property safety and national standards that are enforced by laws and administrative regulations; recommended national standards refer to national standards that are voluntarily adopted through economic means or market regulation in production, exchange, use, etc. However, once the recommended national standards are accepted or agreed to be included in the economic contract by all parties, they become the technical basis that all parties must abide by and are legally binding.

The Standardization Law of the People's Republic of China divides Chinese standards into four levels: national standards, industry standards, local standards (DB), and enterprise standards (QB).

Current implementation standards for lenses

Lens materials - QB2506.2001

Basic parameters of lenses - GB10810.1.2005

Specification of film - QB2682.2005

Specification of transmittance - GB10810.3-2006

Progressive multifocal - GB10510.2

1. Anti-reflective protective lenses

This type of lens is coated with a thin layer of magnesium fluoride on the surface to prevent strong light reflection, making it clearer and not disturbed by strong light. To detect whether the glasses really use anti-reflective protective lenses, you can point the glasses at the light source. If you see purple or green reflections, it means that the lenses are indeed coated with an anti-reflective protective film.

2. Colored lenses

Also known as "dyed lenses", some chemicals are added during the lens production process to make the lenses appear colored to absorb light of a specific wavelength. This is the most commonly used lens type for sunglasses.

3. Tinted lenses

This type of lens has the same effect as colored lenses, but the method of making it is different. It is to apply color on the surface of the lens. The most well-known is the "gradient colored lens", the color is the darkest on the top and then gradually lightens downwards. Generally, sunglasses with prescriptions are mostly treated with tinted lenses.

4. Polarized lenses

In order to filter the glare of the sun shining on the water, land or snow in equal directions, a special vertical coating is added to the lens, which is called a polarized lens. It is most suitable for outdoor sports (such as sea activities, skiing or fishing).

5. Photochromic lenses

Some people also call them "photosensitive lenses". Because the chemical substance of silver halide is added to the lens, the originally transparent and colorless lens will become a colored lens when it encounters strong light for protection, so it is suitable for both indoor and outdoor use.

6. Aspherical lenses

It can prevent eyeball deformation and have a relatively excellent visual effect.

Quality identification of lenses

1. Lens transmittance and optical uniformity test method: Hold the lens about 30 cm away from the eyes and observe the distance through the lens. If the object is clear, without deformation, and there is no jumping when moving slowly, it means that the transparency and optical uniformity of the lens are relatively good.

2. Optical center position test method: Draw a large cross on white paper with a thin line, and the strokes should be clear and straight. Hold the lens and observe the shape of the cross strokes through the lens with one eye. If the strokes inside and outside the lens are not on the same line, you can move the lens so that the cross strokes inside the lens and outside the lens are connected in a line. Use a soft pen to point a small dot at the center of the cross observed in the lens, and this point is the optical center. After the optical centers of the two lenses are pointed out, observe and compare whether the optical centers on both sides are symmetrical, and then use a ruler to measure whether the distance between the two center points is consistent with the pupil distance specified in the prescription. If the cross strokes in the lens are bent, it means that there is a quality problem with the lens.

Precautions for purchasing lenses

1. First of all, you should choose a regular and reputable optometry center to fit glasses, and the quality and service of the glasses are guaranteed.

2. Before fitting glasses, you should have an eye test first, and do not buy blindly.

3. After the glasses are made or purchased, the fitter will fit them according to the face shape. Generally speaking, if the parameters are appropriate, you will feel very clear when wearing new glasses.

4. If you find that the product has quality problems, you should contact the store in time.

Glasses should be cleaned regularly.

It is recommended to measure vision every year to test whether to replace glasses.

 

 

Glasses lenses can be divided into two categories, namely glass lenses and optical resin lenses.

Glass lenses include optical glass lenses and high refractive index lenses (commonly known as ultra-thin sheets). They have high hardness and good wear resistance. Generally, their quality and various parameters will not change over time, but glass lenses are slightly inferior to resin lenses in terms of impact resistance and weight.

Resin lenses are generally much lighter than glass lenses, and their impact resistance is better than glass sheets, but their surface hardness is lower and they are more easily scratched. Resin lenses and coated lenses are soft in nature, so you should be careful not to let the mirror surface directly contact hard objects. When scrubbing, it is best to clean with clean water (or mixed with a small amount of detergent), and then use a special test cloth or high-quality cotton paper to absorb the water droplets on the lens. In addition, coated lenses should be used with caution in places with poor environmental conditions to avoid stains that are difficult to clean.

When choosing a frame, in addition to price and aesthetics, special attention should be paid to the size of the selected frame and the pupil distance as much as possible, because it directly affects the inherent optical quality and wearing comfort of the glasses.

 

 

The identification of the quality of the frame can mainly consider the following points:

1. Frames with good elasticity are generally of better quality.

2. Frames with smooth and shiny coatings are of better quality.

3. Frames with smooth, small and uniform welding points are of better quality.

4. It is better to assemble the parts tightly.

5. The size and shape of the left and right mirror rings must be exactly the same, and the bridge of the nose must be symmetrical.

6. The frames should be comfortable to wear, and not just beautiful.

1. Anti-reflective protective lenses

This type of lens is coated with a thin layer of magnesium fluoride on the surface to prevent strong light reflection, so that you can see things more clearly and without being disturbed by strong light. To test whether the glasses really use anti-reflective protective lenses, you can point the glasses at the light source. If you see purple or green reflections, it means that the lenses are indeed coated with an anti-reflective protective film.

2. Colored lenses

Also known as "dyed lenses", they are made by adding some chemicals to the lenses during the lens production process to make the lenses appear colored and absorb light of a specific wavelength. This is the most commonly used lens type for sunglasses.

3. Tinted lenses

The effect of this lens is the same as that of colored lenses, but the method of making it is different. It is to apply color to the surface of the lens. The most well-known is the "gradient colored lens", the color is the darkest on the top and then gradually lightens downwards. Generally, sunglasses with degrees are mostly processed with tinted lenses.

4. Polarized lenses

In order to filter the glare of the sun shining on the water, land or snow in equal directions, special vertical coatings are added to the lenses, which are called polarized lenses. They are most suitable for outdoor sports (such as marine activities, skiing or fishing).

5. Photochromic lenses

Some people also call them "photosensitive lenses". Because silver halide chemicals are added to the lenses, the originally transparent and colorless lenses will become colored lenses when exposed to strong light for protection, so they are suitable for both indoor and outdoor use.

6. Aspherical lenses

It can prevent eyeball deformation and has a relatively good visual effect.

1. Lens transmittance and optical uniformity test method: Hold the lens about 30 cm away from the eyes and observe the distance through the lens. If the object is clear, without deformation, and there is no jumping when moving slowly, it means that the transparency and optical uniformity of the lens are relatively good.

2. Optical center position test method: Draw a large cross on white paper with a thin line, and the strokes should be clear and straight. Hold the lens and use one eye to observe the shape of the cross strokes through the lens. If the strokes inside and outside the lens are not on the same line, move the lens so that the cross strokes inside the lens are connected to the outside of the lens. Use a soft pen to make a small dot at the center of the cross observed in the lens. This point is the optical center. After the two lenses point out the optical center, observe and compare whether the optical centers on both sides are symmetrical, and then use a ruler to measure whether the distance between the two center points is consistent with the pupil distance specified in the prescription. If the cross strokes in the lens are curved, it means that there is a quality problem with the lens.

1. First of all, you should choose a regular and reputable optometry center to fit glasses, and the quality and service of the glasses are guaranteed.

2. Before fitting glasses, you should have an eye test first, and you should not buy blindly.

3. After the glasses are made or purchased, the fitter will fit them according to the face shape. Generally speaking, if the parameters are appropriate, you will feel very clear when wearing new glasses.

4. If you find that the product has quality problems, you should contact the store in time.

Glasses should be cleaned regularly.

It is recommended to measure vision every year to test whether glasses need to be replaced.

Glasses lenses can be divided into two categories, namely glass lenses and optical resin lenses.

Glass lenses include optical glass lenses and high refractive index lenses (commonly known as ultra-thin lenses). They have high hardness and good wear resistance. Generally, their quality and various parameters will not change over time, but glass lenses are slightly inferior to resin lenses in terms of impact resistance and weight.

Resin lenses are generally much lighter than glass lenses, and their impact resistance is better than glass sheets, but their surface hardness is lower and they are more easily scratched. Resin lenses and coated lenses are softer in nature, so you should be careful not to let the mirror surface directly contact hard objects. When scrubbing, it is best to clean them with clean water (or mixed with a small amount of detergent), and then use a special test cloth or high-quality cotton paper to absorb the water droplets on the lenses. In addition, coated lenses should be used with caution in places with poor environmental conditions to avoid stains that are difficult to clean.

When choosing a spectacle frame, in addition to price and aesthetics, special attention should be paid to the size of the selected frame and the pupil distance, as it directly affects the intrinsic optical quality and wearing comfort of the glasses.

The following points can be considered to identify the quality of the frame:

1. Frames with good elasticity are generally of good quality.

2. Frames with smooth and shiny coatings are of good quality.

3. Frames with smooth, small and uniform welding points are of good quality.

4. Frames with tight assembly of parts are preferred.

5. The size and shape of the left and right mirror rings must be exactly the same, and the bridge of the nose must be symmetrical.

6. The frame should be comfortable to wear, and beauty should not be pursued blindly.

 

 

Modern eyeglass frames are part of fashion and are no longer just medical devices. When people wear glasses, they do not want to expose their own problems, but hope that the frames can play a decorative role, cover up their shortcomings and highlight their strengths.

(I) Shape

According to the geometric shapes determined by the main skeleton structure of the face, the face shape can be divided into 6 categories: square, rectangular, round, inverted heart and oval. The above classification is not absolute, and the specific face shape may be different from each of the above, but it is very helpful for analyzing the face shape and choosing the right frame, highlighting the advantages, covering up the shortcomings, and giving people a sense of symmetry and balance. For example, a square face wearing a round frame can eliminate the feeling of too obvious edges and corners, and the same square frame will increase the angularity of a round face.

In some other places, similar phenomena occur. For example, a plump person wearing vertical striped clothes will look slim, and wearing horizontal striped clothes will make him fatter. People with rounder faces tend to have straighter hairstyles to increase the sense of contour, and rarely have curly hair.

Another basic principle for choosing frames is that the width of the frame should be roughly consistent with the width of the temporal side. A frame that is too wide will appear too cumbersome and will increase the aberration of the lens.

1. Square

Square faces are relatively short, with prominent jawlines and angles. It is important to note the two characteristics of square faces: square and short. Using round frames, especially those with round bottoms, can reduce the feeling of overly obvious angles.

There are two ways to "lengthen" the face:

1.1 This method is the most important: choose a frame with a smaller height. If the frame is too high, it will occupy most of the face and make people feel that the face is shorter;

1.2 If possible, choose a frame with a higher temple position, which will make the face appear longer.

2. Rectangular

Like a square face, people with this face shape also have obvious jaw angles, but the difference is that the face is longer. It is still necessary to use a round frame to alleviate the angles, but the face shape needs to be shortened.

Opposite to the square face: choose a frame with a larger height and the temples in the middle, so that the frame can occupy an appropriate part of the face.

3. Heart-shaped

The heart-shaped face is also called an inverted triangle face, which is characterized by a wide forehead, prominent cheekbones, and a narrow and pointed jaw. This face shape is not balanced from top to bottom, with the upper part larger and more prominent than the lower part. It needs to wear a frame with the opposite appearance, that is, a wider bottom to increase the width of the lower half of the face. A lower temple position can also help improve this effect.

4. Inverted heart face

The inverted heart face also feels unbalanced, with a narrow forehead that gets wider as it goes down, so its jaw is wide and more prominent. This face shape is relatively rare, and the principle of frame selection is opposite to that of the heart-shaped face, requiring a frame with a high temple position and a narrow bottom.

5. Round face

A round face is completely opposite to a square face, so the principle of frame selection is basically the opposite of that of a square face; a frame with more obvious edges and corners is needed to improve the contour of the face, but at the same time, the "lengthening" principle of a square face is also needed, that is, a frame with a lower height and a higher temple position.

6. Oval face

An oval face is known as an ideal face shape, with no particularly prominent skeleton and no obvious flaws to cover up. However, this "ideal" face shape will also derive a lack of shape, so it is necessary to apply the above principle to "lengthen" or "shorten" the face shape according to the situation.

Treatment of nose shape and eye shape

The above is a reference principle for frame selection based on the overall appearance of the face, but sometimes the aesthetic flaws of facial details require special treatment. For example, if the nose is too straight, this defect can be covered up by wearing a low nose bridge or double-bridge frame. Similarly, wearing a frame with a high nose bridge can make a small nose appear larger.

For those with close eyes, you can wear a frame with a light color at the nose bridge and a gradually darker color towards the temple. The opposite is true for those with wide eyes.

Generally, the top of the frame should be parallel to the brow arch and at a similar height, that is, the same height as the brow arch or slightly higher (if the frame slides down, the top should be flush with the brow arch). If the wearer has a high brow arch, it is better to choose a dark frame than a light one, which will highlight the height of the wearer's eyebrows and make people feel that there is another eyebrow.

People generally divide colors into two categories: warm colors with orange as the base tone and cool colors with blue as the base tone. Most people like to choose clothes that match their skin color, which can show personality characteristics.

Although I understand that the style and color of the frame are selected from an aesthetic point of view, I have to explain a few points:

First, these are just basic theories. Fashion is always changing and personal tastes are different, so the wearer's wishes are the most important.

Secondly, other reference conditions for frame selection need to be considered: function and feel, which may conflict with fashion standards.

In addition, the most important thing is that fashion principles are only to help choose, not absolute.

 

 

There are two functional factors to consider when choosing a frame:

(i) The frame dominates the function of the lens.

When choosing a frame, the interaction with the lens should be considered: the larger the frame size, the larger the effective diameter of the frame, the larger the minimum lens blank required, and the thicker and heavier the lens after edge cutting. Therefore, high-profile lenses and aspherical lenses require small, symmetrical, round or square frames, and frames with too long meridians are not suitable. Progressive lenses require frames of appropriate height, that is, the vertical distance from the center of the pupil to the bottom of the inner groove of the lens ring is at least 22 mm.

For highly astigmatic lenses, the meridian direction with the highest mirror power needs to be considered. For example, for lenses with +6.00/-4.00*180, a narrower and taller frame needs to be selected, and the height of the frame should be relatively large so that the thickness of the top and bottom edges will not be too thick. For lenses with +6.00/-4.00*90, a wider and shallower frame should be selected.

(ii) Purpose of wearing.

When choosing frames, you need to consider the purpose of wearing glasses. Some frames may be suitable for daily wear, but may not be suitable for people with special requirements; while some frames are only suitable for wearing in certain environments.

Comfort of wearing glasses.

When choosing suitable frames, you also need to consider the comfort of wearing. Factors that affect wearing comfort include the weight of the frame and glasses, which depends not only on the weight of the frame material, but also on the size and thickness of the frame and lenses. In addition, the fit of the frame will also affect the wearing comfort, and the frame needs to be correctly selected and adjusted. The importance of frame wearing comfort cannot be ignored. There are no fewer people who complain about uncomfortable wearing of frames than those who complain about vision problems with glasses.

Comprehensive consideration.

There are often contradictions between the frame selection criteria such as frame aesthetics, frame function and wearing feeling. At this time, you need to understand which aspect is the most important, and sometimes even need several pairs of frames to solve different contradictions.

Of course, in addition to the above, you also need to have a certain understanding of the quality of the frame itself. When you have a pair of glasses in your hand, you should observe it from the following angles.

(1) Look at the surface: Try to choose temples with clear and shiny surfaces, without defects, scratches, bruises, corrosion, peeling, etc.

(2) Look at the "logo": Regular manufacturers print the brand name on the frame in addition to the product number and size.

(3) Look at the shape: Pull the temples apart and lay them flat to see whether the body and temples are tilted at a certain angle, whether the frame is the same size, whether the various parts of the frame are symmetrical, whether the metal frame with spring legs has the same elasticity, and whether the various parts are finely made.

Protection of glasses

1. Wearing and removing glasses with one hand will destroy the left and right balance of the frame and cause deformation. It is recommended that you hold the temples with both hands and wear and remove them in parallel to the cheeks.

2. When wearing and removing glasses, generally fold the left temple first to avoid deformation of the frame.

3. It is recommended to rinse the glasses with clean water and dry them with a paper towel, then wipe them with a special glasses cloth. You need to hold the frame wire on one side of the mirror and wipe the lens gently to avoid excessive force that may cause damage to the frame or lens.

4. When not wearing glasses, please wrap them with a glasses cloth and put them in the glasses case. If temporarily placed, please put the convex side of the glasses upwards, otherwise the lenses are easy to be scratched. At the same time, glasses should avoid contact with corrosive items such as insect repellents, toilet cleaning products, cosmetics, hair spray, medicines, etc., avoid long-term direct sunlight and high temperature (above 60°C), otherwise it is easy to cause the lenses and frames to deteriorate, deteriorate, and discolor.

5. Go to a professional store for regular plastic adjustment. The deformation of the frame will cause a burden on the nose and ears, and the lenses are also easy to loosen.

6. Do not use glasses during intense sports to avoid strong impacts that may cause lens breakage and eye and facial injuries; do not use worn lenses to prevent light dispersion from causing vision loss; do not look directly at the sun or strong glare to avoid eye damage.

How to clean glasses

The principle of cleaning glasses is to keep them bright and clean, not contaminated with oil and dirt, and avoid scratching the lenses. You can use neutral soap or special detergent to clean it, then rinse it with clean water and dry it with lens paper or soft tissue. Many people have the habit of wiping the lens with the corner of clothes, handkerchiefs, etc. This is an incorrect action because rough materials can easily scratch the lens. To clean the gaps between the frames, you can use a soft old toothbrush to gently scrub and remove dust.

Be careful when collecting glasses

You should also develop a fixed habit of placing glasses. First wrap the lens with flannel, then close the left frame, and then close the right frame. To prevent the glasses from being under heavy pressure, you can place the glasses in a hard glasses collection box.

Maintenance of contact lenses

The light and thin contact lenses are close to the eyeballs. Once they are contaminated, they will immediately and directly damage the eyes. Therefore, cleaning and maintenance must not be lazy.

Out of the mud without staining

Except for patients with eye diseases, general contact lenses will suffer from three kinds of pollution: one is external pollution, such as dust, grease, cosmetics, and detergents in the air. The second is the eyes themselves, such as protein and mucus secretions in tears. The third is contamination by bacteria and mold. Therefore, in addition to being careful to avoid scratches, cleaning and maintaining contact lenses must also thoroughly achieve the three tasks of cleaning, sterilization, and protein removal.

In principle, although some cleaning solutions are effective, they can cause allergic irritation to some people's eyes. Therefore, when purchasing contact lenses, you must ask clearly about the maintenance system that best suits your living habits and physiological conditions, and do not mix different maintenance systems at will. Generally speaking, there are several key points to pay attention to when choosing a maintenance system:

1. Approved by the health authority.

2. Safe for the eyes, no allergic or irritating reactions.

3. Good cleaning effect.

4. Completely sterilize.

5. Conform to living habits.

6. Simple and easy to use.

7. Reasonable price.

Scrub the lenses by hand: Just like if ordinary dirty clothes are not scrubbed first and thrown directly into the washing machine, it is impossible to remove stubborn dirt. Contact lenses must be scrubbed by hand for more than 30 seconds to achieve a cleaning effect. Research reports indicate that hand-washing of lenses can effectively remove impurities and sediments on lenses more effectively than any machine. In addition, tap water or boiling water have no cleaning or disinfecting effect and should not be used to clean contact lenses.

Regularly replace contact lens lenses: Contact lens lenses are different from ordinary glasses lenses. No matter how well they are cleaned and maintained, there will still be a few microorganisms left on the lenses. Even if they are not used frequently, the lens material will naturally become old after 1 to 2 years. At this time, they should be discarded and replaced with new ones to avoid hurting the eyes.

Contact lens lenses should not be stored in physiological saline: physiological saline has no bactericidal effect. If used to store lenses, it is easy to breed bacteria and cause eye infections.

The protein components contained in tears are very easy to adhere to the lenses and are very stubbornly deposited on the lenses. Even daily cleaning cannot completely remove them, and the longer they accumulate, the more difficult it is to remove them. They will cause redness and photophobia in the eyes, discoloration of the lenses, stimulate the immune system of the eyes to produce antibodies, and cause diseases such as "giant papillary conjunctivitis". The enzymes in protein-removing cleaning tablets can decompose the protein structure, chop it up, and eliminate adhesion to achieve a cleaning effect. Usually, the work of removing protein can be done once a week.

 

 

Dazzling sunglasses make you active in the sun, so free. In fact, sunglasses can block the sun, but they cannot block pollution and damage, so you need to take good care of them, so as not to lose face.

In fact, the way to maintain sunglasses is the same as maintaining ordinary glasses. You need to develop a habit of cleaning, folding, and storing. It’s just that sunglasses are often taken off and put on, and they will be scratched if you are not careful, so there are some small details to remind you: when there are stains on the sunglasses, don’t use your fingernails to pick them, which will easily scratch the surface.

When sunglasses are not worn, many people will hang them on their heads, collars or pockets. At this time, the body movement range should not be too large to avoid tearing or crashing. Or some people will put them in a handbag. It is recommended to put them in a hard glasses case first, and then put them in the handbag to prevent the lenses from being worn by small things such as keys, combs, copper coins, or contaminated with cosmetics such as lipstick.

No matter where you store the sunglasses, remember to keep the mirror facing up.

Eyeglass frame maintenance

Keep clean: Sweat or oil on the skin can easily corrode the metal part of the frame. Cleaning the glasses every day is very helpful to extend the life of the glasses.

Avoid sunlight: If the glasses are placed in a place where the sun is easily exposed for a long time, the frames will easily fade due to light and heat decomposition.

Wipe the glasses correctly: Dry them with a special cloth for glasses. Do not let the lenses touch hard objects, do not wipe the lenses with your fingers, please wipe them with a clean lens cloth to reduce lens wear.

Store correctly: Do not put the front of the lens facing down. If not in use, try to put it in the glasses case. If you do not wear the glasses, please wrap the glasses with a lens cloth and put them in the glasses case to avoid damage.

 

 

Store the glasses properly. When you take off the glasses temporarily, do not let the lenses touch the table. That is, let the glasses be in the frame with the arms retracted, the foot arms down, and the lenses up. If you sleep at night, you should put your glasses in a glasses case to prevent the lenses from being worn, crushed, or broken. The glasses case should not be too soft, otherwise long-term squeezing may cause the foot arm (trumpet) to deform, and the glasses will have a certain tilt when worn, affecting vision.

When wiping the lenses, you should prevent wear and tear. If there is dust or dirt on the lenses, you can wipe them gently with flannel or silk cloth. Do not wipe them with clothes, fingers or other things casually. This will wear the lenses and reduce transparency. In the long run, the lenses will be opaque as if covered by a layer of mist; if there is oil or other dirt on the lenses, breathe on it to make the dirt wet and then wipe it gently with a lens cloth. Do not carve it hard or scrape it with hard objects. When children are doing physical education or other intense activities, they should take off their glasses and put them in the glasses case. If the children's glasses are damaged, or the glasses cannot correct the vision to normal, they should go to the hospital for examination and optometry in time. Wear suitable glasses again to protect the children's eyes.

The glasses worn by children mainly have a therapeutic effect on the eyes, and also have a certain cosmetic effect.

Whether the size of the frame is appropriate or not is directly related to the improvement of children's vision and the development of vision.

According to the characteristics of children's liveliness and activity, frames are mostly made of plastic or plexiglass. This kind of frame has a wider side groove, the lenses are firmly installed, and the texture is soft. It is comfortable for children to wear and not easy to be damaged. There are fewer indirect eye injuries in children. And the price is cheap, which is a popular frame.

The size of the frame should be appropriate. Some parents and children think that larger frames look better, and some think that smaller frames are not easy to fall off. These are not comprehensive. Because the position of the pupils of children's eyes is directly opposite the center of the lens (optical center), and the lens and the surface of the eyeball are kept at a position of 12mm, it can play a good correction and treatment role. If the frame is too large, the eyes are far away from the optical center and lean to the inside of the glasses, and the effect of a prism occurs, causing symptoms of visual fatigue such as blurred vision, decreased vision, sore eyes, headaches, etc., and aggravating the development of refractive errors. If the frame is too small, the eyes will lean outward.

This is the past and present of glasses. It can be said that glasses are the crystallization of human wisdom. Its evolution spans nearly a thousand years and integrates technology, aesthetics and pragmatism. With the development of glasses materials, manufacturing technology, craftsmanship and design, glasses have evolved from reading tools to wearable smart terminals. The evolution of glasses reflects the eternal pursuit of human beings for clear vision.