4 ms·
We can stare at a burning campfire and barely get damaged. Long term exposure is another thing. The emitter power would have to be insanely high, or some kind o
by barelyauser 4y ago
We can stare at a burning campfire and barely get damaged. Long term exposure is another thing. The emitter power would have to be insanely high, or some kind of laser.
- drdaeman 4y agoYes, but a campfire emits a lot of visible light, so our eyes adjust accordingly. While we're not cats with their amazing pupil dilation, we have some too. If one wears an IR-shiny hood, they may be at higher risk in the low-light conditions, if their eyes adjust to the dark, brain not realizing they're flooded with IR.
- barelyauser 4y agoRetinal damage is not the only kind of damage the eye can be subjected to. The cornea has no blood flow to cool itself and is fully exposed to incoming radiation.
- analog31 4y agoA campfire has radiance limited by its temperature. It can put out a lot of power, but that power can't be focused to a high energy density at your retina. An LED can be nearly a point source, and can deposit a lot of power at a small spot, i.e., "almost a laser." Moreover, being invisible, an IR LED doesn't cause your pupil to close. And LEDs have gotten powerful enough to be dangerous. The regulations for optical radiation exposure now cover LEDs as well as lasers.