Is all EM radiation light?

[DrJohn]

And surely different people perceive different ranges of frequency or wavelength with their eyes, at both the red and violet ends of the "visible" spectrum. Just like different people can hear sounds in different frequency ranges.

While using a UV-Vis spectrometer, I found I could see a little bit into the IR and the UV range. The puzzled look on the students faces made me look at the dial I was turning, to realise I could but they couldn't see what I was pointing at.