Visors are typically supposed to help protect hockey players but sometimes they can cause trouble, too.
For instance, Flames rookie Matthew Tkachuk found himself in a precarious situation on Thursday night when the stick of a Canadiens opponent, Alex Galchenyuk, got lodged in between his helmet and visor. The awkward entanglement basically rendered both players useless as play continued around them, so a nearby referee blew the whistle for a stoppage.
The stick was quickly dislodged from the helmet without much issue.
I would imagine such a situation would cause a brief bit of panic for the player with a stick jammed just inches from his face, but thankfully Tkachuk escaped the incident without a scratch. It's not something you see every day (though it did already happen earlier this season) but it's still pretty funny to watch as long as nobody loses an eye as a result.