Eye protection for RLT?

[burnt1970]

Can anyone suggest a good place to get near-infrared eye protection for a modest price? I had an ignorant notion that some sort of eye protection could be purchased at a local drug store or sporting goods store, though I've been proven wrong. I just received my red/near infrared device today, but cannot really use it until I get eye protection. I tried to create something, though the light was so bright it penetrated everything. I did use it on my neck, just to see if I would have any adverse reaction. Nothing yet!

[DukeCity]

Tanning salon?

[Capri]

I don't think tanning goggles are suitable, as they are primarily for blocking out UV rays and not NIR. You need to find some that block out IR light, and thats not easy. When I did a Google search the only eye protection I could find that guareenteed to block out all NIR light were industrial style. Unless of course, you want to pay $125 for the Acnelamp ones.

This is all pre-supposing you need eye protection. For the moment I'm erring on the side of caution and not using NIR just yet.

[moomy]

would lining tanning goggles with foil work??

[moomy]

check out

http://members.misty.com/don/irfilter.html

Absorbing IR, Passing Visible

This one is more difficult, since sharp short-pass filter dyes seem to be hard to find in any way.
If some significant absorbtion at visible wavelengths is tolerable, and degree of absorption of different visible wavelengths is tolerable, then there may be a solution.

One option is just that, solutions of copper compounds in water largely absorb most infrared. Copper compounds used must be of the more common "cupric" or "copper II" valence, not "cuprous" or "copper I". These have a very gradual cutoff, and absorb visible red light greatly, and also yellow and orange significantly, and these absorb yellow-green a bit also.

The filters used in acetylene welding goggles absorb IR more than visible, especially if they are glass rather than plastic. Green glass sunglasses are a milder version of this, and offer some infrared absorbtion.

Someone posting to Usenet in May 1996 suggested Schott KG-1 glass and Hoya HA-30 glass filters. He believed these might be in use in some video cameras to attenuate IR and/or make the spectral response of silicon photodetectors more like that of the human eye. Please beware that such glass filters probably do not completely block IR and probably also partially block red visible light.

To pass a specific band of wavelengths and greatly block (mostly reflect) just about everything else, use dielectric interference bandpass filters. They are very effective.
However, they are usually quite expensive, and the passband shifts to shorter wavelengths and often gets narrower and often gets less transparant for light rays hitting the filter in a non-perpendicular manner.
These filters are available from Edmund Scientific.
A few of these are sometimes available from a few surplus dealers. Check the ads in Popular Electronics, Electronics Now, and other magazines related to fields in which such filters might be useful.

[Capri]

You need to find some that block out IR light, and thats not easy.

I meant to write "NIR", sorry for any confusion.

[Twickle Purple]

From this thread: http://forum.rosaceagroup.org/viewtopic.php?t=4914&start=0

LED Light Therapy Research

source (https://plus37.safe-order.net/heelspurs/a/led/led_research.html)

Eye Safety

Strong blue LED's are dangerous to your eyes! White LEDs have been studied for safety, but I wouldn't stare at them because they have blue frequencies in the white. Strong green LEDs have 1/15th the risk of blue. Strong and focused Red and yellow LEDs appear safe, but I would not stare directly at them for more than a minute. If you find a 10,000 mcd 660 nm Red, be careful.

The ACGIH does not seem to have a safety factor based on time of exposure (TLV) for simple LEDs, but it has two categories that can apply to them. One is the TLV for laser light, but lasers are different because they really focus the light in one spot which is much more likely to cause harm. The link at the bottom of this paragraph is a well-researched article that strongly claims you don't need to treat LEDs as lasers when it comes to safety. The other TLV is for light at a range of wavelengths and time exposures, which is good. Blue LEDs may harm the eyes from a photochemical injury called the "blue light hazard". I have personally been harmed by a blue LED key ring (blue photons have much more energy per photon - that's why red light does not affect night vision very much). I had a spot in my vision for months after a 2 second exposure. Distance from such a narrow-beam, strong blue LED only makes the AREA of damage on your retina smaller, not that damage is less likely to occur. Red, yellow, and green also have photochemical risks, but for LEDs, only green has the remote possibility of causing harm (if it's high power with a narrow emission angle). Bright visible light may also harm the retina from thermal activity. Blue is thermally 10 times more dangerous than the others. Reasonably powerful LEDs in red, yellow, and green are also thermally safe. But they are brighter at narrow wavelengths that we have evolved to cope with, so I still consider staring at them for more than a minute to be risky. Infrared light > 770 nm may harm the retina and lens from thermal activity, but has more risk for the lens. Damage to the lens may take the form mainly of cataracts. Infrared should be less than 10 mW/cm^2 if it's applied for greater than 15 minutes. For less than 15 minutes, mW/cm^2 should be < 1800 t^(-0.75). This means 83 mW/cm^2 is safe to the lens for up to one minute. Suppose you're using an excellent 50% efficient LED at its maximum power dissipation of 100 mW. Anything stronger will have difficulty dissipating heat and it's difficult to find more powerful 5 mm LEDs in red and infrared. That's 100x0.50=50 mW light output, but if you place it directly on the lens, it's an exposure in an area of only about 5 mm in diameter, or 0.20 cm^2, so 50/0.2= 250 mW/cm^2 light intensity. So by using the TLV equation above, it appears up to 15 seconds is safe when applying one of the most powerful types of 5 mm infrared LEDs directly to the eye. So, it's possible to increase the risk of cataracts when treating macular degeneration with red and infrared LEDs. From another source: "Near-infrared thermal hazards to the lens (associated with wavelengths of approximately 800 nm to 3,000 nm) with potential for industrial heat cataract. The average corneal exposure to infrared radiation in sunlight is of the order of 1 mW/m^2. By comparison, glass and steel workers exposed to infrared irradiances of the order of 80 to 400 mW/cm^2 daily for 10 to 15 years have reportedly developed lenticular opacities (Sliney and Wolbarsht 1980). These spectral bands include IRA and IRB (see figure 49.1). The American Conference of Governmental Industrial Hygienists (ACGIH) guideline for IRA exposure of the anterior of the eye is a time-weighted total irradiance of 10 mW/cm^2 for exposure durations exceeding 1,000 s (16.7 min) (ACGIH 1992 and 1995). Thermal injury of the cornea and conjunctiva (at wavelengths of approximately 1,400 nm to 1 mm). This type of injury is almost exclusively limited to exposure to laser radiation. " Note: For visible LEDs, Use L= 1000 x mcd/(683 x P) in place of L x (change in wavelength) in the TLV equations. For infrared, use mW/(SR x 1000). The distance from the LED does not change the danger for equations with L in them. The reason for this is because the ACGIH values each and every rod and cone in the retina, and light from a further distance has the same strength for each rod and cone it hits - it is weaker only because it affects a smaller number of them. If you want a better article on the retinal eye safety of LEDs and lasers read this (https://plus37.safe-order.net/heelspurs/a/led/led_safety.pdf) (but they don't address lens safety, do not give an mcd example for blue, and don't discuss focusing that new LED plastic cases use.

[burnt1970]

OK, so some of what I am reading is telling me that there really is no danger with using no protection for Red and NIR, while other things state the opposite. Thing is my device is so bright, it shoots right through my lids with extreme brightness. I like the foil concept. I may try to get creative, rather than spending $100+ for protection, which may not even be necessary.

[Skywolf]

Would Mylar screen that better? We had an eclipse, near total, a few (Ok, many, Im old, I talk) back. I bought, and so did many others gathered at the lakefront some mylar glasses, look like the 3D glasses fom days of old. But we were able to look at the eclipse without burning our retnas to dust. I would not reccomend that as light gets in the sides and stuff, but this thread put me in mind of that.

Laura

[burnt1970]

Now I'm just really shocked. So many people on this board suggested to me that I should try RLT because it is supposed to have great results, but no one can point to a location that sells the proper eye protection for using NIR?? I've tried all creative methods at home, though the light comes blasting through everything, it's so bright! So now I've had this thing for a week, but cannot even begin to use it for fear I'm going to burn my eyes out.

[Capri]

Briefly, there are only really 2 'types' of RLT, Visible Red(VR) and Near Infra-red(NIR), though you can have a combination of VR and NIR. I think the jury is still out on whether you need NIR or not, some use it some don't. As a note of caution you may want to research whether you want to use goggles with NIR, and they must block out NIR - normal tanning goggles are probably not suitable. If I could recommend then I would say just start with VR, but others may disagree, and they maybe right, I don't know. I would still use goggles or some form of eye protection with VR just in case. Most units are LEDs, there are not many flurescent tubed ones.

This is what I wrote when you initially asked about RLT. You should really have reseached eye-protection before buying a unit, and if NIR concerns you, as it does me, gone for just a visible red unit. There are plenty of posts on here in terms of whether users think you should wear goggles or not, we're not experts so you need to exercise your own judgement on this one.

Acnelamp recommend the following glasses for NIR treatment:

http://www.acnelamp.com/product.php?id=1901-p

[Twickle Purple]

Now I'm just really shocked. So many people on this board suggested to me that I should try RLT because it is supposed to have great results, but no one can point to a location that sells the proper eye protection for using NIR??

I have the metal goggles from acnelamp, which most folks find to expensive. They bothered my eyes and I stopped wearing goggles altogether.

There are two mindsets here about goggles: some use them, some don't.

No need to be shocked, chances are you didn't get a response because this has been covered a few times. Check out the archives or use the search engine.

[Miki]

if you keep your eyes closed throughout the session; would goggles still be neccessary?

[burnt1970]

I just got done with my first session. I purchased $2 tanning goggles and stuffed them kleenex, as silly as that sounds. I tried so many things, even solid objects, but light always came blasting through. I had the device sitting on a shelf and was about 6 inches away from it. I found I tilted my head a bit downward because the direct exposure was exceptionally bright to my eyes, even with the obstructions. I don't know if all devices are this bright, but I can't imagine making it through one session without some sort of protection, and not having caused some damage. Even though I'm minimizing the light coming through, I'm still concerned about the exposure. I guess time will tell.

I addition to NIRLT, I started taking Zinc Gluconate a couple of weeks ago, and just purchased Zinc Oxide sunblock. The left side of my face got terribly burned by the flourescent lights at work on Friday. They also cause little bumps to appear from time to time. It's a completely exposed light, no cover on it. I'm thinking of looking for another job partially because of this reason. I guess I could ask my manager if they could cover the light somewhat, but I bet they would think me crazy when I explain to them why...

[moomy]

check out this website...

http://www.protecdirect.co.uk/Product.asp?i=1815&n=IR%2FUV+Goggles

[moomy]

I have been looking into eye protection, and have found that green lenses are good for absorbing red rays, including infrared or near infrared.

There are many welding goggles around with green lenses. Perhaps these, worn over normal goggles and with eyes closed would lead to more protection??

here are some green goggles I found on ebay.

http://cgi.ebay.co.uk/BRAND-NEW-WELDING-LIGHTWEIGHT-SAFETY-GOGGLES_W0QQitemZ230019211565QQcategoryZ11900QQtcZ photoQQcmdZViewItem