These kinds of articles are so misleading especially for the vast majority of the population that don’t apply critical thinking to what they read.
Btw, I really need to thank this post. For the past few days I’ve been wondering why my eyes were strained so bad in the evening. Then this post popped up and triggered me to check my night light settings on my PC and that’s when I realized a recent update caused the night light to reset to off. I just turned nigh light back on and my eye strain is gone pretty much immediately! For those affected by eye strain in the evening, try turning on nigh light or night shift. It really works! Blue light really is bad in the evening!
Yep. But remember the free market in ideas is at work. Industry finds it far more profitable to produce blue-white emitting LEDs than to go to the trouble of designing and producing those same basic emitters with a complex and pricey phosphor coating to intercept that blue and make the output warmer. Same reasoning works for flashlight makers — cool blue-white is cheaper.
Not to mention the market disruption that will be caused when those basic blue-white emitting products are displaced by the newer violet-emitting LEDs. There’s a real scramble going on to fight against the medical advice.
Violet (which is above 400nm) is visible light, although it takes a whole lot of it to trigger the visual perception of light.
Look at the chart, human vision is (slightly) sensitive down as far as 400nm
That may be the increasingly yellow lens that goes with aging, blocking the shorter wavelengths.
Fortunately LEDs are narrow bandwith light sources, so it’s possible to pick an emitter within the violet (above 400 nm) but outside the also narrow range of blue
{peaks in the blue portion of the light spectrum around 460 nm, most effective in the range between 446 and 477 nm}
that affects the human blue receptor.
Yeah, violet photons are going to pack more energy than blue, somewhat less than UV, and I’d clearly want them completely absorbed by the phosphor, not leaking out the sides of the emitter the way we see making blue rings around yellow hotspots in flashlight beams.
You’re quite right to suspect there may be serious problems when people start hyping “no blue” or “retina safe” violet-pumped emitters without close attention to the wavelengths. New problems, that is.
A great experiment is underway ….
Any photon from somewhere in the far blue on to higher energies can knock electrons off of molecules, which is not healthy.
Personally I think violet light is even more harmful to our eyes than blue despite I don’t have any scientific evidence to prove it. Violent is a shorter wavelength and higher energy than blue. I would love for someone to prove my assumption wrong but unless there is solid evidence proving violet is less harmful than blue, I will take blue over violet for day-to-day ambient lighting.