Red and Near Infrared Light and Eye Safety - Seeing Is Believing
At GembaRed we want to make sure that people have access to the full truth about eye safety with red light therapy. Of course, there is good potential that an appropriate dose of Photobiomodulation is beneficial to eye health.
As we have mentioned in several blogs, too much intensity can quickly lead to biphasic dose response, tissue heating, or even burning. Most people will agree that the eyes are much more sensitive to heat damage than the skin. So we need to be extra careful with the eyes versus the rest of the body.
Another huge problem is that most companies claim to emit >100mW/cm^2, which we have repeatedly proven to be false. However, this irradiance claim gives people a false sense of relative safety. Since they are using lights that claim to be 100mW/cm^2 without any damage. When in reality, their light is outputting closer to 40 mW/cm^2.
If someone were to obtain a light that ACTUALLY emits >100mW/cm^2, then that could be hazardous to the eyes. This isn't scaremongering, this is straightforward and defined by the industry. If you don't believe us, check our references. The companies that make these high intensity claims won't tell you the truth about eye safety.
With Red and Infrared we have to worry about high intensities causing photothermal (heat) injuries. Unlike Blue or UV which also causes photochemical damage.
One analysis shows that the eye can only tolerate 80mW/cm^2 of IR LED for less than 30 seconds! Any more would risk having thermal damages. [1]
The recommended limit that the eye can only be exposed to is 10mW/cm^2 for less than 1000 seconds (16.7 minutes). This comes from the International Electrotechnical Commission document IEC-62471.[2]
The IEC-62471 also states that a safe limit of only 57 mW/cm^2 for less than 100 seconds! [2]
So if you think you have a device that actually emits >100mW/cm^2 at 6 inches, you have to take extra care to protect your eyes! Only a few seconds could lead to damage at that high of intensity. Luckily for your eyes, they actually emit less than 50mW/cm^2 at 6 inches.
We can see how if books and manufacturers promote these unrealistically high intensities, we would actually be seeing a lot of eye damages caused by this light panel industry. If someone was following these false guidelines and actually got ahold of these unsafely high intensities, then that would be problematic.
In fact, we recently had a conversation with a person that suffered eye injury by staring into a "therapeutic" near-infrared light. They told us that they wish they found GembaRed's information sooner....
This is why we need an industry that is committed to accurate and honest measurements and educating consumers about responsible usage. Too much intensity is not a good thing.
So companies need to decide. Are they making unsafe lights, or over-exaggerating their intensity numbers?
[1]
https://www.researchgate.net/publication/50291066_Eye_Safety_Related_to_Near_Infrared_Radiation_Exposure_to_Biometric_Devices?fbclid=IwAR3SnL0_j9tfinYog46jNZj45Th0dX4oblm74KoQgEiFXSYcgsh73pcGVa4
[2]
https://www.renesas.com/us/en/doc/application-note/an1737.pdf