Are anti-blue light glasses really useful? Is it necessary to wear them in daily life?

Rumor: It is necessary to wear anti-blue light glasses

Everyone who buys glasses has been recommended "anti-blue light glasses". Whether you buy them for your children or yourself, these glasses seem to be It has become a must-select. Choosing it will be better for your eyes and even prevent myopia.

Interpretation of the truth:

I believe everyone has been recommended "anti-blue light glasses" when buying glasses. Whether you buy them for your children or for yourself, these glasses seem to have become Required. It seems that choosing it is better for the eyes and can even prevent myopia.

But in fact, most consumers may not even know what blue light is.

Today we will talk to you about blue light, anti-blue light glasses, and some "routines" of lens blue light detection pens.

What is Blu-ray?

Blue light is a part of visible light, with a wavelength in the range of 400~500 nm and colors of blue and purple. It is the part of visible light with the highest energy and closest to ultraviolet light.

We are often exposed to blue light in our lives, such as sunlight, TVs, computers, tablets, mobile phones, LED lights, etc. Blue light is distributed in these light sources.

The hazards of blue light are mentioned in the GB/T 20145-2006 | standard. At the same time, in 2018, Chinese ophthalmologists also made a detailed review of the pros and cons of blue light on the eyes. (Zhi-Chun, Zhao, Ying, et al. Research progress about the effect and prevention of blue light on eyes[J]. International Journal of Ophthalmology: English Edition, 2018(12):1999-2003.)

The blue light band that is harmful to the retina is high and short-wave blue light mainly concentrated between (415~455nm).

Long-term excessive blue light radiation can cause chronic light damage to the cornea, lens and retina of the eye.

If you look at cool-colored electronic screens for a long time at night, such as mobile phones, tablets, computers, etc., it will disrupt people's natural sleep rhythm. Especially for children and teenagers who are in the growth and development stage, it is recommended to reduce the use of electronic products before going to bed.

Blue light is not only harmful. It affects the body's biological clock and regulates circadian rhythm.

During the day, there is more blue light, but it is significantly reduced in the evening, so people will form the habit of working during the day and resting at night.

At the same time, it plays an important role in producing dark vision and affecting refractive development.

Blue light glasses and detection pen

There are two main types of anti-blue light glasses on the market. One is film-based anti-blue light, which means coating a layer of film on the surface of the lens to prevent harmful effects. Blue light is reflected.

One is that the base material is anti-blue light. By adding an anti-blue light factor to the lens base material, it absorbs and blocks harmful blue light.

For anti-blue light glasses, what really needs to be blocked is the high-energy short-wave blue light that can penetrate the lens of the eye and reach the retina, that is, the blue light in the (415~455nm) band.

Therefore, blocking this part of blue light is the purpose of anti-blue light glasses.

In recent years, the problem of myopia among teenagers has become more and more serious, and more and more people are wearing anti-blue light glasses.

Some optical stores, when customers buy glasses, will take out "anti-blue light lenses" and "blue light test pens" to demonstrate, such as this:

Put one underneath If the card is illuminated with a "blue light pen", the lens can block the light source and prevent it from passing through, which proves that it is "anti-blue light glasses".

We collected two pairs of glasses from our colleagues and tried them, and found that one could not see through, while the other could.

It seems very intuitive at first glance, but here is a question:

What is the band of light emitted by this pen?

The label of the "Blue Light Test Pen" indicates in small letters that the wavelength of its light source is 405 nm±10.

In other words, the test pen verification only shows that the lens can block the blue light of 405 nm±10 wavelength, but it cannot determine whether it can block the blue light of the 415~455nm band.

In our lives, whether it is LED lights or electronic products (mobile phones, tablets, computers, etc.), the peak of the blue light emitted is around 450nm. This kind of pen just takes advantage of the differences in different wave bands.

Are anti-blue light glasses really necessary?

The anti-blue light glasses on the market used to have uneven quality due to the lack of unified standards.

It is worth mentioning that the national standard for anti-blue light was officially implemented on July 1 this year. The standard clearly lists the light transmittance requirements for four different spectral ranges.

I believe that the anti-blue light glasses market will be well regulated in the future.

Aside from these, we would like to give you some tips on anti-blue light glasses:

1. Anti-blue light glasses are not necessary.

Children are still in the growth and development period. Since the background color of some anti-blue light glasses is yellowish, it may affect visual development. It is not recommended to use anti-blue light measures on a daily basis.

2. Prevent blue light ≠ prevent myopia.

There is currently no direct evidence that blue light causes myopia, so parents do not need to worry too much about the so-called "blue light hazard".

3. Adults do not need additional anti-blue light measures.

If symptoms such as visual fatigue occur, just look far away and reduce the time of continuous eye use. The recommended 20-20-20 rule is to look at an object at least 20 feet away for at least 20 seconds every 20 minutes.

4. For those who have special requirements, such as long-term high-intensity computer workers, etc., if you must wear anti-blue light glasses, try to choose a big brand.

Eyes are a wonderful gift we are born with, and it is not that difficult to protect them.

Reduce exposure to electronic products before going to bed, avoid playing with mobile phones or reading books in environments with poor background light, and rest your eyes by looking far away every 20 minutes. These can protect your eyes.

Now, put down your phone and go see this beautiful world together.

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