Justin Langer's helmet manufacturers are looking into means of developing their product further to provide extra protection. Langer, one may recall, was hit in SA, and missed 3 tests after that. The injury got a lot of attention as Langer was reportedly keen to bat, despite the pain and doctor's warnings, in case he was needed in that nail-biting run chase. His captain went on to say that he would have declared, had Langer insisted on batting.
However much I admire Langer's grittiness, having read how prone he's been to being knocked out through bouncers, I can't help but think that in his case the problem is in the head, not on it.