After Nerdist Industries was founded in 2008, our logo quickly became associated with all things geeky, nerdy, and pop culturey (?). But unless you’re a warning sign enthusiast, have taken any engineering classes, or are just generally in-the-know, you may not be aware our where the logo actually comes from. What’s nerdier than lasers?

The Nerdist logo is based on a traditional European-style laser radiation warning sign (above). Why would you need a sign to tell you that? You intuitively know not to look into a laser pointer like you know not to look into the Sun. Well, signs like this are important because you can’t always see the danger lasers pose.

Laser safety is grouped into seven different classes. The sign above is generally used to indicate lasers that are above “Class 2.” Lasers at and below Class 2 — most laser pointers — are decently safe so long as you don’t stare into the beam. But even if you do get an accidental flash of these lasers to the eye, your biology saves you. Your blink reflex automatically triggers when flashed with a laser and effectively cuts off the beam. The exposure is short enough that no damage is done.

Then comes Class 3 and above. Lasers of Class 3B (like those in CD and DVD drives) and Class 4 (scientific, medical, and military lasers) are powerful enough that our blink reflex is too slow to stop damage from occurring. You shouldn’t even glance at the relfections of the most powerful lasers, hence the sign.

And what happens to you when your blink cannot beat a laser? Well, not to get too morbid, but because our eyes act like lenses for light, a laser pulse can be focused to an intensity on the retina 200,000 times higher than the entering pulse. That causes retinal burns. And if the laser pulse is short enough, it can cause localized boiling in the fluid of your eye, a shockwave, and again, serious damage. That’s why you pay attention to the sign!

The laser safety sign is especially important when infrared lasers are around. Because we cannot see them, infrared lasers won’t trigger our blink reflexes, allowing damage to be done without our knowledge.

So the next time you see the Nerdist logo, prepare for a deluge of geeky goodness. Just make sure there are no lasers around first.