Helmet differences?

I've noticed over these first two weeks of play that there seems to be two different helmets worn, even between players on the same team.
One is the usual smooth surfaced "uni-body" (for lack of a better description) helmet which we have scene for years, if not decades.
The other helmet has a three-sided cutout piece near the front, and seems to have more holes along the upper sides.

I assume the second helmet is a new version that attempts to deal with helmet impacts in a new way, in an effort to reduce concussions, but that is an assumption.

Has anybody else noticed these new helmets, and know anything about them?

Any modifications you see to the helmet shell is obviously geared to better head protection. The air vents have evolved about as far as they ever can, so head protection is the only other possible reason to arrive at the current new ones you speak of. They certainly have better face masks also, it seems.

Also, it wasn't something we have "scene", but rather something we have seen. We're not talking about a film here.

Freakin' autocorrect. :x
And I usually proofread my posts. Missed that one.