What type of electromagnetic energy is invisible to the human eye?
The electromagnetic spectrum is vast, ranging from the smallest Gamma waves at
Just above our view is the infra-red section, and just under is ultra-violet. Why our eyes only evolved to see such a small part of the spectrum, I don't know. But thanks to this, Any electromagnetic energy that is smaller than 400 nanometers or larger than 700 nanometers is invisible to the human eye.
I hope that helped!