After a year away from YouTube, the ever-energetic [Styropyro] has returned with whiteboard in hand to remind us just how little we actually know about lasers. In the last month he’s really hit ...

The videos from [styropyro] are always amusing and informative. However, ironically for him, he is alarmed that many green laser pointers are more powerful than they are supposed to be.

“This laser is several times over the limit at which a direct hit to the eyes would blind you instantly and forever,” Styropyro says early on, “so that’s why I wear these safety goggles.