[EarthLaunch]

I looked into that for VR headset eye tracking, which uses IR lights plus cameras to see the eyes inside the dark headset.

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....

[dogben]

Thanks. So that 30W lamp in another comment might be a safty hazzard if someone in close range stares at it and the beam is tightly focused.

[risenshinetech]

You're right.

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.

[darkwater]

The beam is not going to be tightly focused, if it needs to cover a big chunk of a stadium at once

[krisoft]

Yes. The manual from the manufacturer recommends wearing specific green tinted safety glasses if you are standing closer than a meter to their transmitter while it is on.

[numpad0]

I guess this device can be modified to take visible red lights with some redesign, if you'll be really concerned with that.