About Blue Light Blocking Glasses

Misunderstanding

First of all, a misunderstanding is ruled out for everyone, that is, we often see glasses salesmen use blue light pens to block blue light. In this way, under blue light pen illumination, glasses can basically block all blue light. Many people think that this is the effect of anti-blue light glasses In fact, otherwise, this method may block only purple light. The so-called blue light pen may emit only purple light, and the glasses block is also purple light. It does not really block blue light. Currently, most blue light pens on the market are counterfeit. The principle that the emitted wavelength is shorter than 400-450 nanometers causes artifacts, giving the illusion that blue light is blocked, but it is not.
Secondly, we must pay attention to the anti-blue light transmittance, light transmittance and chromatic aberration of the lens. The anti-blue light transmittance is generally above 35%, and the transmittance needs to be maintained above 90%. The lower the color, the better.

Principle

No matter what kind of anti-blue light glasses, there will be more or less yellow, the reason is simple, not related to technical issues, but involves simple optical knowledge.
The optical three primary colors are: red, green, and blue. These three primary colors constitute the "white light" in our vision. When the blue-proof glasses filter the blue, the remaining red and green mixture becomes the "yellow" in the vision.
The same principle, the LED GaM chip emits blue light and YAG (yttrium aluminum garnet) phosphors are packaged together. When the phosphor is excited by blue light, it emits yellow light. As a result, blue light and yellow light are mixed to form white light. So when you look at the LED light source, it will turn yellow.

We provide the following methods to test

1.Cell phone test method:
Put the anti-blue light glasses on the screen of the opened mobile phone, and then observe whether the covered area is blueish. If so, it is anti-blue light. The principle is that the blue light emitted by the mobile phone is blocked by the lens and reflected on the screen of the mobile phone.

2.Flashlight irradiation:
Judging by the color reflected by the lens, if there is blue light in the back area of ​​the lens, it means that most of the blue light has passed through the lens, and the lens has a poor anti-blue light effect; if a large piece of blue light appears in front of the lens, it means that most of the blue light is reflected back by the lens, Good blue light removal effect

3.Visual observation:
The biggest difference between ordinary lenses and anti-blue light lenses is the coating interlayer. Really anti-blue light lenses, the naked eye can see that the surface has a special light yellow light.

4.Grating spectrometer:
The grating spectrometer displays the number of filtered blue light. The blue light spectrum is 380-500nm, and the grating indexer can show how much light is filtered in each band. This is the most formal measurement method, but it is also difficult for ordinary people to operate. It can also be tested with a blue light pen.

5.Try on experience method:
After wearing anti-blue light glasses, you can look at the phone or computer screen. If the light has a noticeable yellowish and soft feeling, it means that the glasses have anti-blue light.
 

Suggest

It should be noted that the use of anti-blue light glasses can reduce the damage of blue light to the glasses, but we must take care of our eyes. On the one hand, we must avoid excessive use of electronic products, and on the other hand, we must avoid the exposure of strong light to eyes . Don't use electronic products for a long time and close distance. You should rest for ten minutes every half an hour to relax your eye muscles.
 

Sheen Kelly Blue Light Blocking Glasses

SHEEN KELLY insists on using high-grade materials to make frames, and promises to use lenses with blue light blocking rate ≥30%. Effectively block harmful blue light, retain true colors as much as possible, relieve eye fatigue, and protect vision health.