Is high power IR lamp safe for eyes?
Here someone did some calculations [0].
> The International Commission on Non-Ionizing Radiation Protection's Guidelines of limits of exposure to broad-band incoherent optical radiation (0.38 to 3 µm)[1] states:
> "To avoid thermal injury of the cornea and possible delayed effects on the lens of the eye (cataractogenesis), infrared radiation (780nm < > λ < > 3μm) should be limited to 100 W m⁻² (10 mW cm⁻²) for lengthy exposures (> 1000 s)"
0: https://docs.eyetrackvr.dev/getting_started/led_safety#about...
1 (pdf): https://docs.eyetrackvr.dev/safety/ICNIRP_optical_radiation....
While we're at it, we should make sure no one goes up to the massive speaker system and puts their ear right up to the speaker cone too.
- UV is baby step towards X-rays. It's technically super blue light, but it's entering region where lights start splitting chemical bonds and bleaching stuffs like pathogens and human eyes.
- LASER is perfectly parallel beams of light. Because it's perfectly parallel and do not diverge, it behaves like sun under magnifying glass at all points in its path, which can be dangerous when the "sun" is high and "glass" focusing it tight.
High power IR lamp illuminating audiences from afar is almost safe as any searchlights. IR lasers can be dangerous. UV lamps are not so safe, UV lasers would be bad.
To first approximation, in the typical situations regular people deal with lasers. Inverse square rule still applies; laser light does spread out with distance.
That nitpick aside, your description is spot on.
When it's beamed widely in your general direction from a larger distance, you'll be fine.
It can also happen with (the wrong type of) UV lights.