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Why Do We Need Blue Light-Blocking Glasses?

Mar 21, 2019

1. What is blue light radiation?


First of all, the blue light we are talking about here refers to high-energy short-wave blue light. Here is Google's explanation for high-energy short-wave blue:


High energy short-wave blue light is a relatively high energy light having a wavelength between 400 nm and 450 nm.


Here, in particular, blue light is not all harmful blue light, what is really harmful is short-wave blue light within 400 to 440 or 450 nm, and blue light between 450 and 500 nanometers has a function of adjusting biological rhythm, sleep, emotion Memory, etc. are all related to it, but it is beneficial to the human body.


Moreover, short-wave blue light will definitely cause harm to the human eye, which is related to the irradiation intensity and the irradiation time. When the illumination reaches a certain level, it lasts for more than two hours, and it is possible to damage the retina.


2. In which occasions do you have harmful blue light radiation?


Blu-rays of everyday life can be seen everywhere, but the main source of harmful blue light that comes into contact is the LED LCD screen.


Today's LCD screens use LED backlights. Since the backlight requires a white light effect, the industry uses a blue LED to mix a yellow phosphor to form white light. Since the blue LED is a main hardware, the blue spectrum in this white light has a peak, which forms what we call the harmful blue light.


Our current life is full of LED LCD screens, such as computers. This is the most important source of Blu-ray threats for office workers, followed by mobile phones. Especially with the rise of smart phones, blue-radiation objects have also extended from office workers to families. Children and the elderly, and this phenomenon is getting worse.


3. How much damage does the short-wave blue radiation have on the eyes?


As already mentioned above, ordinary blue light does not cause damage to the glasses. What is really threatening to the eyes is high-energy short-wave blue light, which causes the amount of toxin in the macular area in the eye to increase, which seriously threatens our eyes.


As early as 1966, Nell and other studies found that exposure to blue light can cause damage to retinal cells, leading to decreased or even lost vision.


Among them, the high-energy short-wave blue light with a wavelength between 400-450 nm has the greatest damage to the retina.


At the 2010 International Light Association Annual Meeting, the world's top optical experts unanimously pointed out that short-wave blue light has extremely high energy and can penetrate the lens to reach the retina. Blue light illuminates the retina to produce free radicals, which cause the retinal pigment epithelial cells to die. The decline of epithelial cells causes light-sensitive cells to lack nutrients and cause vision damage, and these damages are irreversible.


4. Can anti-blue glasses really protect your eyes? How does it work?


The first answer is yes. Anti-blue glasses can effectively block harmful blue light from entering the fundus and greatly alleviate eye discomfort such as visual fatigue. Of course, what we call anti-blue light glasses mainly refers to anti-blue lenses.


At present, anti-blue lenses are divided into two categories: reflective blue light and absorptive blue light.


Reflective anti-blue light is a film that reflects the harmful blue light when the lens is added. The anti-blue film will have a light yellow color, so that the screen light will be soft and the lens will be transparent.


Absorbing anti-blue light is the addition of materials during the fabrication of the substrate. The lens material absorbs harmful blue light. Such lenses have a base color and a very pale yellow color.


Both methods have their own advantages, but all have a reducing effect on harmful blue light. Anti-blue lens is not the best defense, it is the best, and it is not the best for all-weather use. In fact, the anti-blue lens should be called: special lens for electronic products, outdoor wear does not need to wear anti-blue lens, anti-blue lens It can be reduced by about 30% for blue light, so that the short-wave blue light is filtered and the beneficial blue light is preserved, which is more scientific for the human body.