From what I can tell, if you pick a color near the extreme of the visible light spectrum, let's say red, and trace a path across the spectrum until you are outside of the visible range, at some point the red color will begin to darken and dim until it's invisible (ie. black), indicating that you are now outside the range.
If this is the case, does that mean that if you were to observe a powerful enough light source emitting solely that dim frequency, that it could be blinding to your eyes? By blinding, I don't think I mean literally blocking the rest of your vision, but more as in painful or overly-stimulating, the same way a bright white or bright blue light can affect a person's sight.
It is hard to imagine being blinded by a dim light, because usually when you increase the intensity of the light, the saturation of the color will increase, until it appears bright. In this special case though, the color is already fully saturated to begin with, so no matter how high you increased the intensity, it will always appear 'dim'. Is this right?
EDIT:
Comments have shown that the word I was searching for is dazzled, not blinded. There are some great answers here explaining the harmful effects of this type of light, and this is a legitimate interpretation of what I am looking for. The essence of the question, however, is to understand if a near-IR or near-UV light could have a dazzling effect on the observer's eyes.
Best Answer
Yes indeed, infrared light (the wavelengths beyond those of red light) can be very harmful to your eyes even though you don't see them. The same applies for ultraviolet light (the wavelengths beyond those of violet light).
You can read more under the topic of laser eye safety. People that work with lasers need to use safety glasses if these lasers fall within certain categories. These include infrared and ultraviolet lasers.