One day, the NHL might be a place where visors are mandatory for every player. Until then, here’s Marc Staal taking a puck to the eye in a horrific scene during the New York Rangers’ game vs. the Philadelphia Flyers on Tuesday night.
Warning: It's not for the squeamish, and there's blood involved.

Here are some additional replays:

With 14:15 left in the third period, the Flyers Kimmo Timonen took a shot from the point. It was deflected on the way to the net by Jakub Voracek and was redirected into Staal’s face, bloodying the Rangers defenseman. He left the ice and did not return.
Here’s an animated .gif of the incident that you won’t be able to un-see.
Please recall that Staal battled back from a concussion in 2011, suffered on a hit from his brother Eric in March of that year.