Everything can be folded, and wearing glasses is no exception.
In winter, wearing glasses foggs.
In the winter when masks are used to masks, glasses always fog up because of mouth and nose exhalation.
In the winter when you are accustomed to masks, watching movies, glasses and 3D glasses are hung on the bridge of the nose together, and the glasses are always foggy because of the mouth and nose exhalation, or double-layer fog.
Image credit: NTU
In the near future, the spectacle family may be able to get rid of this pain forever.
Permanently de-fogging lenses are coming
No one likes foggy glasses, cleaning wipes, anti-fog spray must be always available, but most anti-fog solutions are not curative, it is a never-ending repetition.
On February 22, Nanyang Polytechnic in Singapore announced the development of a new process that will permanently fog-free polycarbonate lenses.
In simple terms, the researchers applied a durable double coating to the lenses in two steps, one layer of silica film and the other titanium dioxide film.
First, treat lenses (or other plastic surfaces) with oxygen plasma, a common industrial method of cleaning surfaces to improve film adhesion.
Second, using pulsed laser deposition technology, silica and titanium dioxide are evaporated in a vacuum chamber, which rises accordingly, and then as a thin film, deposited on a plastic substrate located at the top of the chamber until the desired film thickness level is reached.
Compared with similar industrial methods, this method allows better control of the thickness and structure of the film, resulting in a higher quality film. The researchers say the whole process is "quick and easy to implement" and takes about an hour.
So, what is the specific effect of anti-fog?
Glasses fog because water vapor condenses into water droplets, and if the water droplets are diffused into a uniform film that does not hinder vision, it can play an anti-fog effect. The anti-fog performance of the coating is measured by this diffusion rate.
GIF created from: NTU video
The principle of the new coating is similar to other anti-fog coatings, but the process is very fast, taking only 93 milliseconds. You know, our blinking lasts an average of 100-150 milliseconds.
Hot water does not fog. Image credit: NTU
At the same time, the coating exhibits excellent adhesion and durability. When rubbed with a cheesecloth pad, the coating resists abrasion; when cellophane tape is applied to the coating and then peeled off, the coating still bonds to the polycarbonate lens.
The researchers say the coating has more than just defogging and durability.
Image courtesy of Newatlas
One is anti-reflectivity, with coated lenses achieving up to 89% light transmittance, which is about 5% better than the same lens without coating. The higher visible light transmittance allows more light to pass through the lens, and the intuitive feeling is that the clarity is improved.
The other is self-cleaning. Titanium dioxide has photocatalytic power, and when coated lenses are exposed to sunlight (or other ultraviolet light sources), titanium dioxide reacts with organic residues such as bacteria and dirt, thereby removing them.
This innovation can be used not only for eyewear, but also for industrial applications of various optical components, such as protective covers for surveillance cameras. "Self-cleaning" means that monitoring is less obscured by surface dirt and has a clearer field of view.
The research team has filed a Singapore patent for their coating and is seeking to establish an industrial collaboration with plans to bring innovation from the lab to market. They believe that the problem of plastic atomization is a "long-term solution to reduce costs and waste".
Mask and glasses family, how can you effectively prevent fog?
This innovation of Nanyang Polytechnic has hit the pain points of many colleagues of Aifan. As one of the few lucky ones who didn't wear glasses, I had to watch them spit out bitter water and then silently nod my head in sympathy.
"Wearing a mask to fog" is one of the most troublesome problems for the lovers of fans. If you want to solve the problem, you can either start with a mask or start with glasses.
Start with the mask, then reduce the gap between the bridge of the nose and the upper edge of the mask. Based on this principle, the Disaster Countermeasure Division of the Metropolitan Police Department of the Metropolitan Police Agency shared two methods on Twitter.
Image credit: Twitter@MPD_bousai
The first is to fold the uppermost edge of the mask inward by a small strip, so that the upper edge of the mask is more suitable for the face and reduces the leakage of water vapor upwards. However, it should be noted that this method will reduce the protective area of the mask, and it must be determined that the mouth and nose can be completely covered, otherwise it is meaningless to wear a mask.
The second is to put a flat strip of toilet paper or a special anti-fog sponge above the inside of the mask, similar to the first principle. Similarly, there are nose pads that fill the gap between the mask and the face.
Nose pads. Image courtesy of zoff
If you start with glasses, the more commonly used is anti-fog spray or disposable anti-fog wet wipes, nano anti-fog factor can form a protective film on the surface of the lens, prevent water vapor from condensing on the mirror surface, generally effective for several hours or a whole day.
Load efficient anti-fogging agent for anti-fogging glasses cloth. Image courtesy of smzdm
There are also various "folk anti-fog" soil methods, such as cleaning glasses with warm soapy water, because the surfactant of soapy water can reduce the surface tension of the lens and prevent water molecules from condensing into clumps, which is actually similar to that of anti-fog spray. Although effective, it is not recommended for long-term use so as not to harm the lens film layer.
Toothpaste can also reduce the surface tension of water, apply a little toothpaste to the surface of the glasses, and then wipe it with a spectacle cloth, as long as a little residue can produce a defogging effect. However, some toothpastes may contain abrasives that can cause scratches when applied to the lenses.
In addition, before Nanyang Polytechnic, there were already some anti-fog lenses on the market, such as Essilor's ultra-thin anti-fog lens Optifog, which is attached with a top film with anti-fog function, which must be used with anti-fog cleaning mirror cloth with a unique molecular structure.
Unfortunately, its hardness, scratch resistance, antistatic and dust resistance have been reduced, and the lenses must be cleaned with anti-fogging mirror cloth every day, washed with water every two weeks, and replaced every three months after 450 uses.
Therefore, there is no "once and for all" method of de-fog, which can only be effectively anti-fog rather than absolute anti-fog, and it is no wonder that my colleagues are eager to wear anti-fog lenses. Is lens fog bothering you? You are also welcome to share your own go to the fog cheats.
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