Is anti-blue glasses really useful?
For the average person, if not too much contact with electronic products, there is no need to pay too much attention to blue light protection.
If you are in front of the computer all day and your eyes are easily tired, you can consider wearing anti-blue glasses, which will help.
We all know that the screen is not good for the eyes, for the problem of often looking at the computer, office workers show their magic, bought a lot of peripherals to protect the eyes, of which the most frequently used are two artifacts: anti-blue glasses and anti-fatigue glasses.
So, are anti-blue glasses really reliable?
First of all, the widely circulated blue light mainly comes from LED light sources, whose main light-emitting principle is to hit blue light on phosphors to produce mixed light, which looks like white light.
Uch that the amount of blue light in the LED light source is greater than amount of natural light.
In theory, because blue light has a short wavelength and high energy, it can penetrate the cornea and lens, so it is more likely to cause retinal damage.
Does it sound scientific to wear anti-blue glasses?
But there is a saying that “talking about harm regardless of dose is hooliganism.” When we talk about blue light damage, we cannot ignore the two important factors of illumination and exposure time.
As far as our daily contact with the display is concerned, it is unlikely to cause retinal damage. Scientific studies
have shown that short-wave blue light (400-440 nanometers in wavelength) is easy to cause damage to the eyes, while the peak spectrum of LED light sources we use is 450-500 nanometers.
Therefore, for the average person, if not too much contact with electronic products, there is no need to pay too much attention to blue light protection.
However, when blue light encounters small particles in the air, the probability of scattering is higher, which may cause glare.
Therefore, if the proportion of blue light in the light source is too high, the image that is originally focused on the retina will be focused in front of the retina. In order to see objects clearly, the eyes need to adjust themselves and bear a greater burden, thus causing visual fatigue.
Therefore, the conclusion is that for people who need to face the screen all day, their eyes are easily tired, but they can consider wearing anti-blue glasses, although not as magical as advertised, but it will help.
So, how do anti-fatigue glasses resist fatigue?
It starts with the principle of vision. The principle of the eye is similar
to that of the camera, which can see objects at different distances by zooming. The zoom ability of the
eye mainly comes from a structure inside the eye, called the lens, which changes its ability to refract light by changing its shape, flattening or bulging, so that objects at different distances can be seen clearly. The change of
lens shape mainly depends on the ciliary muscle.
When we look far away, the ciliary muscle is relaxed. When we look close up, the ciliary muscle starts to work and contract, which makes the lens thicker and the ability to concentrate light better, so that we can see objects closer.
But if you look close for a long time, the ciliary muscle has been in a state of contraction, which will cause eye fatigue. The principle
of anti-fatigue glasses is simply to reduce the degree below the lens, so that less muscle adjustment can be used when looking near.
For example, if your myopia is 300 degrees, the upper part of the lens is still 300 degrees, which ensures that you can see far and clearly, and the lower part of the lens is reduced by 100 degrees, which makes it easier for you to see near. However, the adjustment of the eyes when they look near will also drive the cohesion of the eyes, that is, the eyes will turn inward.
Through artificial operation to reduce regulation, for a long time, the muscle function that drives the eyeball to turn inward will be affected, so that the normal position of the eyeball changes, resulting in strabismus.
Therefore, if the accommodation function of your eyes is normal, I do not recommend you to use anti-asthenopia glasses.
However, if you really need to look at the computer at close range for a long time, there are problems with your own adjustment, or the adjustment function has declined over the age of 40, you can consider a pair of glasses. After
talking about these eye protection devices, let’s talk about why screens damage our eyes and how we can protect our eyes.
In the medical field, we call a series of eye and visual problems related to the use of video terminals such as computers as video terminal syndrome.
Symptoms include dry eyes, tingling, soreness, photophobia, frequent blinking, blurred vision, unstable vision, visual distortion, diplopia, heavy eyelids and other eye discomfort, as well as headache, dizziness, loss of appetite, memory decline, neck, shoulder, waist and back pain, joint dysfunction and other systemic symptoms.
According to statistics, many people may have visual fatigue after using computers for an hour, and the longer they use them, the more obvious the degree of fatigue, and may also aggravate myopia. There are two main culprits of
video terminal syndrome: one is the characteristics of the display itself, and the other is the state of the eyes when using the display.
1. The characteristics of the display itself The current video terminal displays are self-luminous displays, whose contrast, resolution, image quality, refresh rate and font size jitter may affect the eyes.
If the quality of the display is not high, the parameters are not good enough, the screen is small, in order to see clearly, our eyes need to constantly use the adjustment function to focus, over time, it is easy to appear visual fatigue.
And when the display does not match the brightness of indoor light, the glare generated will also cause eye discomfort and affect the visual quality.
Secondly, researchers tested volunteers and found that when we talk, we blink 15.5 times a minute, but when we face the video terminal, the number of blinks decreases significantly, which makes tears evaporate more and more likely to lead to dry eyes.
Since we are talking about the topic of work sickness, I will give you some practical eye care methods in the office.
First, fit a suitable pair of glasses.
Do not match a pair casually, can see clearly, this is the equipment you wear for a long time every day, there are many fastidious, not only need accurate optometry, but also choose the right product for you.
For example, the size of the frame should match the distance between the pupils of both eyes, and it is not appropriate to be too big or too small. When choosing lenses, we should consider the influence of the degree. If the degree is high, we should choose lenses with high refractive index. Only
in this way can we get better visual quality and so on. Choosing a good pair of glasses is a big topic. We can learn some relevant knowledge.
Some people will continue to wear glasses for many years as long as they are not broken and can see clearly.
In fact, glasses also have a service life, I suggest that you go to re-optometry every two years, check whether the degree has changed, whether the degree of wear and tear of glasses needs to be replaced.
Sometimes your eyes feel sore and uncomfortable, and a more suitable pair of glasses may improve it.
Second, adjust your computer screen to its best condition.
I said earlier that video terminal syndrome is related to monitors, and you can improve it in two ways.
On the one hand, the height of the monitor and the angle of the eye line of sight should conform to the ergonomic structure, that is, the distance between the eyes and the monitor should be greater than 50 centimeters. At the same time, by adding a laptop stand or adjusting the height of the chair, your line of sight should be about 15-20 centimeters higher than center of the screen, which can reduce the evaporation of tears.
On the other hand, the brightness, resolution, flicker rate and so on of the screen should be adjusted to the state that the eyes feel comfortable.
Indoor background light should not be too dark, especially at night, the room should be lit.
Remember to wipe the screen regularly, too dirty not only affects the display quality, but also increases the glare and the burden on the eyes.
Third, we should pay attention to the ambient light source and air humidity.
Ambient lighting is very important, and inappropriate lighting is destroying your eyes all the time.
In addition to paying attention to the impact of stroboscopic and blue light on the eyes, you can observe the illumination and color temperature of the light in your workstation. It is recommended to choose a color temperature ≤ 4000 K and a central illumination of 750lx (Lux), which will be more comfortable for the eyes. When you
buy lamps and lanterns, you can focus on the instructions.
Also pay attention to color rendering and glare.
If you really can’t choose, it is suggested that you should at least choose qualified big brand products in your room and try to choose expensive ones within the budget.
Secondly, when using computers or mobile phones at night, the background ambient light should not be too dark, especially when playing with mobile phones before going to bed, it is recommended to turn on the night light and stay in a very dark environment for a long time, which may induce acute glaucoma.
It’s better not to lie down and play with your mobile phone. If you can’t do it, at least keep your two eyes at the same distance from the screen.
In addition, it is suggested that you put an air humidifier next to the computer to increase the air humidity and relieve the dryness of the eyes.
Fourth, increase the frequency of eye rest.
Close eye use time is the main cause of visual impairment, but many people really can not reduce it, so it is necessary to interrupt the continuous close eye use time and increase the frequency of rest.
You can remember the 20-20-20 principle of looking at a distance of 20 feet (about 6 meters) for at least 20 seconds for every 20 minutes you use the computer.
Or after 45 minutes of work, get up and walk around, pour a glass of water, rest your eyes and move your body at the same time.
Fifth, consciously increase the blink frequency. As we said
earlier, when you look at the screen or drive for a long time, you will involuntarily increase the time to open your eyes, reduce the frequency of blinking, and reduce the stability of the tear film. Over a long period of time, it will affect the structure of the tear film, resulting in dry eyes, blurred vision, etc., so you can consciously blink more.
You can try, after looking at the computer for a while, blink your eyes, do you feel that everything has become a little clearer.
Sixth, don’t stay up late and go to bed early. It
‘s easy to understand that eye discomfort is closely related to mental state. You must have the experience of staying up late without sleeping well and getting up with dry and uncomfortable eyes the next day, but this may be easier said than done.
To sum up, for office workers, eye protection should pay attention to the following points.
First of all, if you often need to face the screen of computer and mobile phone, you must be alert to video terminal syndrome, which is mainly caused by inappropriate display and unhealthy state of watching display.
Secondly, we explore the scientific principles of anti-blue glasses and anti-fatigue glasses to help you choose peripherals reasonably.
Finally, we use six good habits to help you protect your eyes in the process of working and reduce the harm caused by the bad habit of working eight hours a day.
. Focus on not getting lost ~
