Going through gaps definitely happens. Try putting a set of open glasses in front of something round, shooting at it, and see how many rounds end up inside.
Here's a quote from a thread a couple weeks ago. This was with sealed goggles, but they were poorly fitted.
Originally Posted by Berkut
I used to ran Bolles as well, as you mentioned, they leave huge gaps all over the place. After few years of using them had a BB go through the gap over the nose, hit me in the eye. Freaked me right out.