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Q: Will a bright infrared light damage your eyes if you look at it too much? Of course, it depends on what wavelength of IR you are talking about. The near IR (800 nm to 1400 nm) is focused on your retina just as if it were visible light. The only difference is your retina does not have receptors that detect it. If you look at a visible light that is too powerful, you will damage your eyes. If you look at a IR light in this range that is equally powerful, you will do nearly equal damage. And you do not have pain receptors on your retina to know you are burning it. Because you don't detect it, so you wont blink or look away like you would with visible light, IR light in this range is actually more dangerous than visible light. It does not matter that the photons are less energetic, since when you talk about light power, you talk about total energy and not energy per photon.  
If you look at light over 1400 nm, it will be absorbed primarily by your cornea. Since it is not focused by the lens (like the near IR is), it is much harder to get the energy density needed to damage your eye. Also, you can sense pain in your cornea, so you will know that your eye is getting burnt. And the cornea is one of the fastest regenerating tissues in your body, so damage to the cornea is not as catastrophic as damage to the retina. So, unless you are looking at a super powerful light source in this range, it's probably not a concern. Anyways... in short. If you’re planning to make a modification. Be sure to never look at the Sun directly without being 100% sure that you’ve blocked UV and especially IR as it will slowly burn your eyes unnoticed. Learned from my own experience, a quick peak though the telescope was a fact without thinking about the consequences. Stupid of me but hopefully a good warning to you.