Building Biology Environmental Consultant William S. Bathgate discusses the downsides of LED lighting. That includes the hidden costs and the unhealthful high frequency dirty electricity. He has decades of experience in EMF radiation and its amelioration.
hpathy.com
I find this article
NB: I haven't (yet) read this article.
and here are my conclusions:
1. There can be LED lightbulbs that creates dirty electricity, but some LED lightbulbs can work as dirty electricity filters.
Well, that would be surprising (to me).
LEDs uses DC current (from 1,6V for IR and red LED, to 3,8V for violet, UV and white LEDs).
So to create a LED lightbulb, one needs to transform the AC current from the power supply, which is 120V & 60 Hz in North America, and 230V & 50 Hz in Europe, into a DC current of the right (low) voltage.
And to do it in a small volume (the cap of the light bulb), with a light weight, and for a low price.
For that, an electronic circuit is used, called a "switch mode" (or "switching") power supply.
And that circuit generates "electrical noise", or "dirty electricity".
2. I believe this famous blue light problem is not correlated with blue color, but with light temperature.
Do you know what light temperature is ?
en.wikipedia.org
The whiter the light, the more blue component there is in it.
For instance, for sun light :
- around 2000 K
shortly after sunrise or before sunset, when the sun appears as red ;
- up to 5800 K with the sun at its zenith, appearing "white".
And the blue sky itself is around 20,000 K.
BTW, red LED was invented first (1962). Then orange, yellow, green and violet LED were invented in the early 70's.
Blue LED was invented (and sold) in 1993. Thanks to it, white LED was invented in 1995 (and sold in 1997).
To create the white LED, they took a blue LED, put some phosphorescent material over it (producing yellow light), and the mix of blue+yellow lights is perceived by the human eye as white.
(In France, there was a famous humorist named Coluche who made a funny sketch about the detergents -- washing powder then -- which were promoted as "washing whiter than white".)
In fact, the detergent producers added a chemical product (named "optical brightener" in English, or
azurant optique in French) in the washing powder to colour the white in (pale) blue, making it appear "whiter than white" (with the use/washing cycles, linen and clothes tend to become yellowish or greyish).
en.wikipedia.org
Be that as it may, according to science, blue light
is toxic for the human eyes.
Check "retinal phototoxicity" on Google Scholar, or just "blue light toxicity".
In other words, the more natural light (more similar to this outside your window), the healthier for your eyes.
[/QUOTE]
Well... it depends (as usual). "Natural" is not a synonym for "safe" or "healthy".
Same as wild plants (or, more rarely, wild animals) that can be highly toxic, or even lethal for humans.
It's
safe to look directly and lengthily at the sun
only during the first half hour after sunrise, or the last half hour before sunset. (Outside of the tropics, it may be safe during one hour after sunrise / before sunset, but only around winter solstice, when the sun is low over the horizon).
Never do that at noon ! Particularly around the summer solstice (like now), outside of the tropics. That would
destroy one's eyes. (Same for powerful LASERs, etc.)
4. Cataract can be prevented if you exposure [expose ?] your eyes everyday to daylight. Your eyes don't regenerate if not exposured [exposed ?] to daylight everyday.
(Indirect) daylight is the best, for sure.
5. Small incandescent bulb can be good when you read books. It's warm light that don't make your eyes tired.
Indeed (if the power is sufficient).
aaronia.com
