Did you know that glasses cloth is not used to clean glasses?

I believe that many friends who wear glasses do this: after wearing glasses for a day, there will be fingerprints, dust, oil, etc. on the lenses. At this time, in order to clean the lenses, we will blow on the lenses, and then use paper towels or glasses cloth, or even wipe the lenses back and forth with the corners of clothes.

Image source: Paixin Creative

After a long time, everyone will find a problem. There are some places that cannot be cleaned no matter how hard you wipe them. If you look closely, it is not dirty at all, but there are many tiny scratches on the lens. Is this because the quality of the lens is too poor, or is it caused by the above daily operations incorrectly?

1. The correct way to open the glasses cloth

In fact, the real purpose of the glasses cloth is to wrap and protect the glasses, to prevent the glasses from collision and friction in the glasses box, and to prevent the glasses from being damaged. In the past, most lenses were made of glass, which is very hard, so wiping with a glasses cloth will not scratch the lenses. With the development of technology, resin lenses have replaced glass lenses. Although resin lenses have many advantages, their hardness is not as good as that of glass lenses.

Image source: Yitu.com

In addition, the materials of most eyeglass cloths on the market are not fine enough, the gaps between the fibers are relatively large, and the lenses are easily left with dust, tiny particles, and oil stains. In particular, those tiny particles, although they look small, are very hard for the lenses. If you use the eyeglass cloth to dry-clean your glasses without cleaning them, it is equivalent to rubbing the surface of the lens with tiny particles, which will wear out over time. If the wear is just in the middle of the lens, the wearer's vision will be affected after long-term use, resulting in poor correction effect, visual fatigue, blurred vision, etc.

The correct way to use the glasses cloth: Place the glasses on the soft side of the cloth and wrap them, then put them into the glasses case. This will reduce the friction between the lenses and the glasses case, thereby extending the service life of the lenses.

Source: Taken by myself

2. How to correctly clean stains on lenses?

Nowadays, due to various refractive errors or eye diseases, more and more patients need to wear glasses for correction. However, after wearing glasses for a long time, dust, oil and other dirt will inevitably accumulate, especially the dust in the gap between the frame and the lens is difficult to clean.

Image source: Paixin Creative

In fact, when we usually clean the lenses, we are not cleaning the lenses themselves, but the various film layers attached to the surface of the lenses. They seem to be integrated with the lenses. In fact, if the wiping technique is improper, the film layers may be worn, scratched, or even fall off, and eventually be scratched, making the glasses completely unusable. So we should clean them like this: First, take the glasses under running water to rinse the front and back surfaces of the lenses, as well as the dust and dirt on various parts of the frame. If there is no oil stain, rinse the lenses with cold water; if there is oil stain, you need to spray the glasses cleaning liquid directly on the front and back surfaces of the lenses and other parts of the glasses, or use detergent (preferably neutral surfactants), first squeeze a drop on the fingertips and dilute with water, rub the foam and then apply it to every part of the glasses, gently rub the lenses, and then rinse with water. Finally, use a clean, unpatterned paper towel to gently absorb the remaining water droplets in one direction. Be careful not to rub back and forth hard, otherwise the lenses will have horizontal or vertical scratches over time.

Image source: madrolly/adobe/IC photo

For daily cleaning, the above methods are sufficient. Another more professional cleaning method is ultrasonic cleaning, which can clean the stains in the gaps of the lenses and other parts of the glasses. After washing, they will be like new ones. If there is no ultrasonic at home, you can go to a nearby optical shop, optometry clinic, or ophthalmology hospital for cleaning. Note: When cleaning the lenses, you must not use hot water to clean them, because the film layer on the surface of the lenses will be destroyed after contact with high temperatures, and the film will peel off. Do not use facial cleansers or hand sanitizers when cleaning, because some of the chemical components contained in them may have a corrosive effect on the film layer, which will cause the film layer to fall off over time, and may also cause fogging after cleaning. If soap is used, soap scum is easy to form and hide deep in the crevices of the frame. When using running water to rinse the lenses, do not let the water flow too fast to avoid damaging the mirror surface. It is recommended to clean the glasses at least once a day, which can not only extend the service life of the glasses, but also maintain clear vision every day.

Image source: Paixin Creative

3. Are anti-fog wipes for lenses useful?

It is very common for lenses to fog up, especially when eating noodles, hot pot, drinking hot drinks, and wearing masks in winter. The trouble of fogging may appear in our lives all year round, so how can we prevent the lenses from fogging? There is an anti-fog wipe for glasses on the market. Is it useful? The main reason for fogging is that the water vapor in the air liquefies and forms small water droplets when it encounters the surface of the lens. The uneven distribution of water droplets will cause the glasses to fog up. The professional term is "fogging". Water droplets are similar to micro lenses, which refract light, thereby affecting the transmittance and imaging quality of the lens, which is very annoying. The ingredients of anti-fog wipes are mostly fiber-free non-woven fabrics, nano anti-fog agents, ethanol, surfactants, etc. The principle of anti-fog wipes for glasses is achieved through physical adsorption. The hydrophilic groups in the preparation adsorb water molecules in the air, reduce the contact between water molecules and the surface of transparent objects, thereby reducing the surface tension of water, so that water vapor cannot condense into small water droplets, and form a uniform hydrophilic protective film, thereby playing an anti-fog role.

Image source: Yitu.com

Because there is more liquid on the surface of wet wipes, there will be liquid residue on the surface of the lens after wiping it, which takes time to evaporate. Therefore, you should wait for a while before wearing glasses after wiping the lens with it. Before using anti-fog products, you must use the correct method to clean the lens until there is no dust and grease, and then wipe the lens dry. If it is not cleaned thoroughly, dust particles will be left when wiping the lens with anti-fog products, which will scratch the surface of the lens, shorten the service life of the lens, and reduce the anti-fog effect.

Source: Chongqing Science and Technology Museum

Author: He Mei, optometrist at Chongqing Wodi Ophthalmology. Xuan Xu, deputy chief physician of ophthalmology at Chongqing Wodi Ophthalmology. Former deputy director of ophthalmology at Daping Hospital of Army Medical University.

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