I would like to say that there is no sharp division between one kind of wave and the next. The classification is based roughly on how the waves are produced and/or detected.So we can just loosely divide them based on their wavelength but without any strict range.

As far as you question is concerned 462nm can never be infrared because viable light has roughly range from 400nm to 700nm as the name suggests infrared ie.inferior to red that is it comes below red in usual em spectrum diagram.(Note that red light is at higher wavelength region in visible spectrum) so you lecturer had make a mistake (slip of toungue) may be wanted to say UV rays which may be of that wavelength.

I would like to say that there is no sharp division between one kind of wave and the next. The classification is based roughly on how the waves are produced and/or detected.For example, SLF radio waves at 60 Hz may be received and studied by astronomers, or may be ducted along wires as electric power, although the latter is, in the strict sense, not electromagnetic radiation at all we can just loosely divide them based on their wavelength but without any strict range.

As far as you question is concerned 462nm can never be infrared because viable light has roughly range from 400nm to 700nm as the name suggests infrared ie.inferior to red that is it comes below red in usual em spectrum diagram.(Note that red light is at higher wavelength region in visible spectrum) so you lecturer had make a mistake (slip of tongue) may be wanted to say UV rays but that is also wrong.