Yes. I apologize for changing it. I was accused of putting a click bait title, that’s why I changed. Then I had to change the wording in the post as well and went down that rabbit hole. In retrospect I realize I shouldn’t have changed anything. My bad.
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Can I ask you a couple of straight questions and get straight and direct answers?
If the light you see in the video was visible and was flashing in your eyes every 5 seconds for 8 hours a day, would you say it was bad for your eyes?
If yes, why do you think the IR light of same intensity is not?
Sure.
No, it would not be bad for your eyes as the intensity is too low. It would be uncomfortable, and possibly cause an epileptic fit if it was very fast, but it would not cause any damage.
The cells in your eye are constantly regrowing as they are constantly damaged by a variety of things. The most obvious example of this is burn in, if you stare at a bright light source then close your eyes, and you can still 'see' the light. This is because the nerves have been temporarily damaged - or shocked, and need a moment to recover. But this effect is only observable with visible light, not IR or UV, or anything else on the spectrum. This is because your eyes have evolved only to detect visible light - so they are only sensitive to visible light. These cells evolved from simple nerves found all over your body, if you shine a light onto your arm you cannot perceive it, however you can feel the heat if it is strong enough. Again, if you were to hold a hot source over your skin for too long this would cause temporary damage (Burning), which you know will heal as these cells are repaired. The same thing occurs with your eyes, it is possible to permanently damage them but this requires intense light + heat (Often these come together), staring at the sun is not enough to do this, but being close to a nuclear blast would (And obviously have other side-effects).
Essentially, the light coming from an LED - perceivable or not - is simply not strong enough to have any effect on you.
You have mentioned pupils and other elements of the eye before, however these are only there for focusing light onto these nerves, and react to visible light incredibly quickly. Using a camera you can detect other light sources, for example IR, this is because a camera and the human eye work very differently, your eye cannot detect 'invisible' light and so cannot be effected by it. Note this is just 'light' we are talking about, IR light is used for a lot of heating elements because it carries a much stronger level of heat than visible light. However, even if you were to sit in-front of an IR heater for several hours staring directly at it - it's the heat that would cause discomfort, not the light.
For what it's worth I spent 18 months of a Psychology degree studying vision.
