670nm deep red led helps eyesight

[lightdecay]

@ggf31416

BTW given that the vF is 2V or so, the LED efficiency at 350mA is about 450/(350*2) = ~60. We have come a long way from the days of incandescent light.

LED efficiency could be around 60 at 350mA.

Datasheet for SST-20-DR, which is a similar LED, claims:
Wall-Plug Efficiency: typ. 60% @350mA
https://download.luminus.com/datasheets/PDS-003040-Rev-04-SST-20-DR.pdf

[kennybobby]

@jon_slider

“maybe someone wants to buy this light and put it on a meter”

It sounds similar to the Torch in the Study

Walmmart sells basic plastic 9x 5mm lights for 99¢ with 3 AAA cells and a plastic separator for shipping.

If we could get some of those 670nm red 5mm leds if would be easy to swap them in. Really budget lights for sure.

Then you would have the exact format of the study.

[moderator007]

@jon_slider

maybe someone wants to buy this light and put it on a meter

It sounds similar to the Torch in the Study

I see orange in the pic, doesn’t that mean it might be lower than 660nm.

[jon_slider]

@lightdecay

I think lumens are not the best unit of measurement when talking about deep red light for medical purposes.

Im sure that is true, it is just my way of levelling the field

If you have a 670 nm light, and I have a 670 nm light, and we both measure the Lux… then the errors are a constant… other than the difference in our meters

see what I mean?
Im asking for lumens of red, to compare to lumens of red

even though yes, white lumens, green lumens, and red lumens, are not the same.

@kennybobby

If we could get some of those 670nm red 5mm leds

go for it!

@moderator007

I see orange in the pic, doesn’t that mean it might be lower than 660nm.

yes, we dont know the nm of the light in the photo

I just ordered some 660nm to replace my 620nm, but Im not too concerned about needing to find 670…

I dont think there is just one LED frequency that is magic… the study used what they could find, on the cheap…

[RichH]

@Barkuti

@lightdecay

…

Your experiment with staring directly at the sun seems quite extreme, I would love to know more. What exactly did you see? How did it progress as you kept doing it, and what happened when you stopped? Why did you stop?

That happened nearly 11 years ago. What I saw was not of this world, or what others would call hallucinations. By the time I often painted the town red on weekends, and it involved the use of research chemical substances (in early 2008 I was one of the mephedrone pioneers in my country, daring to get a 100g bag of that :person_facepalming: «lovely» substance). I had already attended drug rehab centers, plus many visits to the hospital caused by overdoses, when that happened. It was a @#$% time. Luckily, years later I could reprogram my mind to dismiss the involved negative entities (with paid help).

The progress of the illness was quite fast, although not evident at first. It settled quite fast once I started to notice it, with a prominent small blot in the center of my eyesight and perceptible barrel distortion. To be able to read I learned to focus close to what I needed to read, i.e. when reading from my laptop screen I focused over some letter or word but actually read a tiny word or 2/3 letters before or after. Of course, :person_facepalming: I stopped doing that!

Wed, 07/01/2020 - 21:59

100g bags and staring at the sun?!! That’s helpful, cheers. :person_facepalming:

I’d like to thank G0ose and Glen Jeffreys for bringing some sense to the thread. About red light.

[kennybobby]

No need to rehash and criticize old stuff from over a month and a half ago—that is ancient and we are moving forward on the task, don’t look back.

[hank]

OK, so — Sofirn red light, arm’s length, medium brightness, through closed eyes, for three minutes several days a week.
Is that the protocol recommended

[kennybobby]

With some scotch tape for a diffuser—a diffuser is definitely needed.

The 9 x 5mm light with White Leds draws 260mA, or 29mA each, when using 3 AAA (4.5V). The Vf for the 670nm Reds(AlGaAs) is much lower, 1.8V @ 20mA, and the radiant power is 6mW each at that current. The max continuous current is listed as 50mA.

The radiant power of 40mW/cm2 at the exit of the FL may have come from a total radiant of ~150mW with 450mA current draw from the 3 AAA cells, using 3.8 cm2 area of the 2.2cm diameter lens.

*These torches were produced for the study. There are currently no commercially available torches of the same specification.

**Participants placed their eye over the end of the torch. Eyes could be closed as the red light is not filtered by the eye lid.

example of Vf change by color:

[kennybobby]

Here’s a shot of a 670nm 5mm led from Thorlabs that user RJA built post#46, said it was the one used in the study.

[jon_slider]

@kennybobby

The radiant power of 40mW/cm2…

thank you

Do your calculation inform what output level to use on the Sofirn C01s, with diffusion, and at what distance?

fwiw, 2 layers of scotch tape drop output on my meter, by 25%

[kennybobby]

Finally got the article, here’s a picture of a test torch. Looks identical to the free lights that HF stores (harbor freight or hazard fraught) would give away with any purchase. With a piece of CPVC water pipe over the end as a spacer. The test subjects only used it on one eye. These 9 x 5mm torches don’t usually have any sort of current-limiting device or resistors, so it’s a wonder how the lower Vf of the 5mm 670nm leds would survive with wide open current.

[ggf31416]

Alkaline AAA are their own resistors, and thin wires.

[RichH]

@kennybobby

No need to rehash and criticize old stuff from over a month and a half ago—that is ancient and we are moving forward on the task, don’t look back.

Fair call. I was on the phone reading it, and do have crap eyesight. I got as far as the mentalist boasting about how many drugs he could take, his numerous ODs, and staring at the sun and decided I wasn’t going to learn anything. His post should be removed in my opinion.

Anyway, good to learn a bit more, I got one of the Sofirn’s through.

[kennybobby]

@ggf31416

Alkaline AAA are their own resistors, and thin cables.

i was using a stiff power supply so not current limited, but how much would the alkaleaks limit?

Do you have any data or links that explain the effect?

@ Rich, no worries mate— we just have to laugh to keep from crying, and trying to figure out a home-build or diy solution for testing the red light theory to improve the eyes. It looks like several different approaches, just need to figure out how to limit the radiant power to safe levels.

[Katherine_Alicia]

[quote=kennybobby]

@ggf31416

just need to figure out how to limit the radiant power to safe levels.

Couldn`t you cut a hole in a ping pong ball?

[kennybobby]

That’s an interesting idea, will have to give it a try.

Would you be able to put a battery or power supply voltage to your red leds and take a picture? or compare their color to some of the reds shown in this thread?

[kennybobby]

@jon_slider

@kennybobby

The radiant power of 40mW/cm2…

thank you

Do your calculation inform what output level to use on the Sofirn C01s, with diffusion, and at what distance?

fwiw, 2 layers of scotch tape drop output on my meter, by 25%

i’m going to assume that the 40mW/cm2 figure is at the end of the PVC plastic tube shown in the photo above, and that it is a calculated value based upon the vendor’s radiant power specs, but doesn’t take into account the drop of the diffuser. Maybe i’m wrong and it was a measured value, but a 75% drop due to diffusion would obviously be significant.

i’ll sharpen the pencil a bit later and edit this post.

[ggf31416]

You can always buy the diffuser for $2 extra when buying the C01R or make your own.

i was using a stiff power supply so not current limited, but how much would the alkalines limit?

Do you have any data or links that explain the effect?

Maybe I spoke too loosely, alkalines batteries will quickly drop to 1.3V-1.2V under 0.5 - 1.0A load. Zinc-Carbon ones are much worse and will drop dead under 1.0A load, you can’t just ask more than 0.5A from them, they could limit current by themselves, I guess I was thinking about the Zinc-Carbon ones.

Luminus 660nm LEDs have 2.35V forward voltage at 700mA, the chart you listed says 2.5V at 100mA. To get from 1.2 x 3 = 3.6 to 2.5 you need to drop 1.1V, that’s certainly possible with low spec parts and thin wires, just a bad switch will cause a significant voltage drop, but alkalines batteries would not be enough by themselves.

[jon_slider]

RE: Sunlight has an intensity of 105 and the Red Light Study used an intensity of 40.
40/105 =38%

Propose:
Find the time of day when sunlight is at 38% of its max intensity

result
8:30am sun measures 20 lumens on my meter
11:30am sun measures 53 lumens

Propose:
Look at the sun through closed eyes when the intensity is at 38%
then use a red light to approach a similar intensity, through closed eyes.

result
my 620nm red light, that reads 20 lumens on my meter, held 10 inches away produces an intensity that does not exceed the intensity of the sun at 8:30am

disclaimers
too many to list

---

Red Light Therapy Device for Just $99

“Why is the R-670 better? Our device outputs the same wavelength of the light therapy unit NASA studied extensively.

The R-670 unit is the only full spectrum mobile red light therapy (photobiomodulation) device on the market.

The R-670 uses a simple two minute self-timed dose for accurate and consistent treatment.”

[hank]

full spectrum mobile red light

What? Looks like some advertising copywriter shook too many words out of the adjective dispenser.
Why isn’t it “tactical”??