No fogging technique for glasses with mask (no fogging for glasses with mask)

Recently, many companies have resumed work and production, and many people have resumed work one after another. Whether commuting or in the office, almost everyone wears a mask and pays attention to personal protection.

But wearing a mask for a long time is uncomfortable. If you wear glasses, it is easy to encounter fog…

Masks and haze glasses|Couple girl

Foggy glasses seriously affect vision. Some people will take it off and wipe it, and then put it on after the lens is dry; or pinch the mask to make it fit better. This solution is sufficient for everyday scenarios. But for medical staff who are on the front line of the war and need full body protection, these simple small methods are too extravagant and too unrealistic.

Goggles, like masks, protective clothing, and gloves, are an important barrier to cut off the spread of the virus and protect medical staff. This barrier can also hinder medical work when the goggles fog up. Healthcare workers often work long hours and it can be difficult to change or wipe goggles. It would be nice to have anti-fog goggles to help them out.

The goggles worn by the nurses working on the front line of epidemic prevention are foggy | ***中文网

Various anti-fog methods

We are all familiar with the phenomenon of lens fogging. When the warm water vapor discharged from the human body meets the cold goggle surface, it will condense into small water droplets due to temperature changes and adhere to the goggle surface. These water droplets will refract and reflect light, affect sight, and increase the difficulty of nursing work.

Since the fogging of the lens is caused by the condensation of water vapor into small water droplets, we can start with the temperature difference. When the lens temperature is equal to or higher than the water vapor temperature, the fogging phenomenon will disappear. Japanese hotel bathrooms often have mirrors that don’t fog up because of the heating installed behind the mirrors. Manufacturers of some goggles have also tried to take advantage of this principle. Powered by batteries, the heating element heats the lens, thereby increasing the temperature of the lens and reducing fogging.

There are also manufacturers who want to fix two layers of lenses in the mounting groove on the frame, the inner layer is coated with anti-fog agent, and the outer layer is perforated for ventilation…Although the starting point is good Yes, however, these protective glasses are not widely used for many reasons, such as poor anti-fog effect, high cost and heavy burden. Goggles need to be light and comfortable while protecting them. Therefore, making a fuss about the lenses has become the key to solving the anti-fog problem.

When it is cold, water vapor condenses into water droplets

At present, various medical protective materials are in short supply. method to solve this problem. The most direct way is to prevent exhaled air from contacting the goggles. To this end, they cut the indwelling needle film into suitable long strips and pasted it horizontally on the upper edge of the mask and the skin of the lower eyelid to ensure that the upper edge of the mask fits the facial skin. For an IV drip, we use a patch to hold the needle in place. Even if only 2-3After hours of persistence, there will be pain on the back of the hand when it is torn. Just imagine, if you stick it on the delicate facial skin all day long, what kind of discomfort will it bring? If the film is torn improperly, it is easy to cause skin damage, which may increase the risk of infection for medical staff.

Compared with this, the method of coating goggles with surfactants such as dish soap has been more widely used. This method is not only suitable for hospitals, but also recommended by parents at home. When I was at home because of the epidemic, my mother pointed to the video of applying hand sanitizer on my mobile phone to prevent fogging and asked me if it was feasible. In fact, detergents and body washes both prevent fogging because their surfactants are hydrophilic.

When water vapor contacts the goggles, small water droplets will form due to the drop in temperature, fogging and obstructing the line of sight. However, once the surface of the lens is coated with a hydrophilic surfactant, such as soapy water, shampoo, shower gel, hand sanitizer, etc. , the small water droplets condensed by water vapor will diffuse into small water films. Unlike water droplets, a uniform water film can greatly reduce the diffuse scattering of light, thus maintaining the high transparency of the lens.