[DenisM]

There are wavelength that are invisible to human eye, those are pretty safe unless the energy levels are high enough to burn a hole in your retina.

Then there are wavelength that aren’t focuse by the eyes, the only way to get hurt with these if the energy reaches weapon-grade levels.

[salty_biscuits]

Actually, some non visible wavelengths are dangerous because they don't make you blink.

[godelski]

A lot of infrared lasers are dangerous because of this. Blink response is part of the reason visible lasers are classified differently than invisible lasers.