What is LED (light emitting diode) ? LED's disadvantages, problems, and effects on human beings

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Chinese article: https://lowvisionandcvi.blogspot.com/2018/02/ledipadled_38.html

LED is the most recommended light source nowadays. Apart from light bulbs, it is also used in the background light of electronic display screens, such as your smartphone1 and computer monitors/screens1, etc.


As LED is not too hot and energy saving, it is greatly promoted and is used to replace other more traditional light sources, such as fluorescent tubes, curlicue compact fluorescent light bulbs, and incandescent light bulbs.


However, it is exactly because LED lights produce a fair amount of light in the blue spectrum4 (or called ‘blue light’), that they are so bright!




There is no free lunch in this world; we may be paying a price4 to use LED.

According to a research paper called ‘The Effects of Blue Light On Ocular Health’ 5, written by Elaine Kitchel of the American Printing House for the Blind, the wavelength of blue light is ‘near UV’ 5: 

On the other hand, according to another article ‘Blue light has a dark side’ by Harvard Health Publications of the Harvard University, “Those curlicue compact fluorescent light bulbs and LED lights are much more energy-efficient than the old-fashioned incandescent light bulbs we grew up with. But they also tend to produce more blue light” 4, please refer to: 

Concluding from different researches or articles (which are listed in the reference list at the bottom of this blog), “short wavelength LED street lighting ……legitimately raises the question of whether these new light sources are introducing as many problems as those they are claiming to solve” 3, such as blue hazard6, light pollution2,6, night vision2 in aging eye3, increase glare2,3, poses threat to driving safety at night3 (because of the strong spike of light), “disruption of nature’s light cycles on all flora and fauna”2, “may contain other hazardous metals such as lead and arsenic” 6, blue light even affects our sleep4, causes damage to the retina in eyes1, etc.

So do have a look at the following article 6 and understand what is LED, which you will surely see or use everyday at close distance, and understand its disadvantages, problems, and effects: 

References：

1.      A website in Taiwan called '睛睛這一家', article '藍光是什麼？為什麼螢幕有藍光傷害? (2015-7-9)'
2.      Jim Benya editor: Blue light blues.
3.      Deborah Burnett (2009): Driving at night – how light affects the eyes of aging drivers.

四個網誌: [關注視覺]、[LED與藍光]、[低視能與大腦性視障]及 [Low vision, multiple disabilities, visual impairment and CVI / BVD] Set up four blogs: 1. Care for vision, 2. LED and blue light, 3. Low vision and CVI, 4. Low vision, multiple disabilities, visual impairment and CVI / BVD (Only in English).

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