A 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 L

A 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.