Foreword: Cosmetic Contact Lenses is not a common name of a product, but a registered trademark of Johnson & Johnson Company (registration number: 4233189). The correct product name of "Cosmetic Contact Lenses" as understood by ordinary consumers should be "color soft contact lens". For the convenience of readers' understanding, "Cosmetic Contact Lenses" in this paper refers to "color soft contact lens".

In the prevention and control stage of epidemic normalization, people wear masks most of the time when they go out, and only half of their faces are exposed. Eyes have become a key area of beauty, and Cosmetic Contact Lenses has also become a hot consumer product.

At the same time, more and more nearsighted young people use Cosmetic Contact Lenses to correct their eyesight. They may think that I have to wear glasses anyway, and Cosmetic Contact Lenses with myopia can make me more beautiful!

After noticing this phenomenon, Consumer Report conducted a consumption survey in Cosmetic Contact Lenses, and compared the oxygen permeability of six brands of Cosmetic Contact Lenses and ordinary contact lenses of the same brand.

There are no capillaries in a healthy cornea. In the open state, 8% of the oxygen needed for maintaining basic metabolism of cornea comes from the outside air, 15% from corneoscleral vessels and 5% from aqueous humor. When we wear contact lenses, it is equivalent to adding a "barrier" between the cornea and the air, which isolates some oxygen transmission. So theoretically, the higher the oxygen permeability of contact lenses, the better.

According to the classification, Cosmetic Contact Lenses and ordinary contact lenses belong to "contact lenses". For the sake of eye health, we should also pay attention to the index of oxygen permeability when selecting Cosmetic Contact Lenses, and basically understand the difference between oxygen permeability coefficient and oxygen permeability.

This time, Consumer Report compared six popular Cosmetic Contact Lenses contact lenses and ordinary contact lenses sold by their respective brands in terms of oxygen permeability.

According to the data, the oxygen permeability of some Cosmetic Contact Lenses is low. The oxygen permeability of one Cosmetic Contact Lenses of Hailien, Bausch & Lomb and Cora is less than half that of their ordinary contact lenses.

Li Hua (a pseudonym at the request of the interviewee), a salesperson of optometry products, told reporters that Cosmetic Contact Lenses has more pigment layers than ordinary contact lenses, and the oxygen permeability is usually not very high. However, the reporter found that the oxygen permeability of a Cosmetic Contact Lenses made by Johnson & Johnson, moody and Haichang can be at least equal to that of ordinary contact lenses.

At present, China's national standards do not require the minimum oxygen permeability of Cosmetic Contact Lenses/contact lenses.

in 1984, after a large number of experiments on hydrogel contact lenses and silicone elastic lenses, Brien Holden and George William Mertz, pioneers of modern optometry clinical research and vision care research, found that the minimum oxygen permeability Dk/t value of contact lenses should be 24 1-9 (unit: (cm/s) [mlo2/(ml mmhg)] if corneal edema is not caused, the same below. More importantly, Holden and Mertz found that the minimum oxygen permeability Dk/t of contact lenses should be 87 1-9 if corneal edema is lower than 4% by wearing glasses overnight.

Subsequent studies have pointed out that the average corneal edema rate is 3.2% when people sleep without glasses. According to the regression curve analysis of oxygen permeability and corneal edema of Holden and Mertz, the minimum oxygen permeability Dk/t of contact lenses should be 125 1-9 when wearing glasses overnight.

Although these values are not mandatory limits, they have been recognized by the optometry industry organizations such as the International Association of Contact Lens Educators.

In other words, when consumers choose contact lenses or Cosmetic Contact Lenses, it is best to choose products with oxygen permeability Dk/t value above 24 1-9; If there is a need to wear it overnight, it is best to choose a product with a Dk/t value above 125 1-9. It is worth reminding that the reporter noticed that the unit of oxygen permeability in the manual of contact lens/Cosmetic Contact Lenses products is generally (cm/s) [mlo2/(ml HPA)], and to judge whether the value meets the above suggestions, it is necessary to convert the unit into (cm/s) [mlo2/(ml mmhg)].

unit conversion:

1 (cm/s) [mlo2/(ml HPA)] = .75 (cm/s) [mlo2/(ml mmhg)]

Wearing Cosmetic Contact Lenses/contact lenses with low oxygen permeability or for a long time may cause corneal hypoxia, conjunctival congestion and corneal epithelial cells. If there is hypoxia for a long time, the surrounding tissues will grow and regenerate. Blood vessels enter the cornea and feed the cornea through blood, that is, "corneal neovascularization".

In addition, Shi Weiyun, president of Shandong Eye Hospital, has publicly stated that he will encounter a lot of eye complications caused by Cosmetic Contact Lenses in clinic. Because Cosmetic Contact Lenses is worn on the cornea, the cornea is at risk of being infected. Once infected, it may cause corneal opacity, and the vision will decline irreversibly. In addition, it may also cause corneal hypoxia. He particularly emphasized that young people are not advised to wear Cosmetic Contact Lenses, especially inferior Cosmetic Contact Lenses. After being soaked in tears, toxic pigments are harmful to the eyes.

At the same time, he suggested that people who wear contact lenses or Cosmetic Contact Lenses should pay attention to eye hygiene, especially when wearing glasses. When necessary, you can follow the doctor's advice and use artificial tears or antibiotic eye drops to help reduce the complications of wearing glasses.

In fact, in order to obtain higher oxygen permeability, consumers can focus on the products of silicon hydrogel. There are many tiny oxygen channels in the matrix of silicon, which makes oxygen molecules pass through the lens freely and maintain good oxygen permeability. On the other hand, it is hydrophobic, so that the oxygen permeability of the lens is not limited by water content. For ordinary hydrogel lenses, the water content is the main carrier of oxygen. Theoretically, the higher the water content, the higher the oxygen permeability. However, in order to maintain water content, the lens needs to absorb water from tears, which is easy to cause dry eyes when worn. Studies have pointed out that silicone hydrogel lenses can obviously improve the dry eye caused by hydrogel lenses.

generally speaking, the oxygen permeability of silicon hydrogel products is better than that of ordinary hydrogel products. Consumer Report also collected some information about silicone hydrogel products on the market. They generally have high oxygen permeability, but their prices are correspondingly higher.

It is worth mentioning that compared with ordinary hydrogels, silicone hydrogels are relatively hard, and some wearers may need some time to adapt.

Li Hua said that many agents and consumers in Cosmetic Contact Lenses have not established the basic cognition that "Cosmetic Contact Lenses belongs to medical devices". They think Cosmetic Contact Lenses is a beauty product, just look good.

In fact, the product names in Cosmetic Contact Lenses are generally "color soft hydrophilic contact lens" and "soft corneal contact lens". According to the classification catalogue of medical devices in National Medical Products Administration, it belongs to the third category of medical devices.

according to article 4 of the general provisions of the measures for the supervision and administration of medical device operation, medical device operation shall be classified according to the risk degree of medical devices. There is no need for licensing and filing for operating Class I medical devices, filing management for operating Class II medical devices, and licensing management for operating Class III medical devices.

In other words, Cosmetic Contact Lenses is not an ordinary beauty consumer product, but belongs to the third category of medical devices with high risk. Consumers must pay more attention when purchasing. First, make sure whether the favorite product has a "medical device registration certificate number", which is usually printed on the product packaging, and then log on to the official website of National Medical Products Administration to check whether this number corresponds to the product you purchased and whether the number is within the validity period.

the eyes are the windows to the soul. More than 8% of external information is input to the human body through visual channels. Therefore, we must be kind to our eyes.

For consumers, Consumer Report does not recommend wearing Cosmetic Contact Lenses for a long time, nor does it recommend using Cosmetic Contact Lenses as a tool for correcting eyesight for a long time. Before purchasing contact lenses/Cosmetic Contact Lenses, you should go to a regular medical institution for an ophthalmic medical examination to confirm whether you are suitable to wear such products. Corneal curvature and corneal diameter need to be measured before fitting to confirm the base arc and diameter of the fitted lens.

For Cosmetic Contact Lenses manufacturers, Consumer Report called on them to indicate the oxygen permeability of Cosmetic Contact Lenses in a clear position on the Cosmetic Contact Lenses packaging box or on the publicity page. Because most of the products are only marked in the inner boxes or instructions, and the products themselves are in plastic packaging, it is difficult for consumers to give clear guidance when purchasing.