I've just had one fitted for the living room. Brand new, safety glass etc... DH came home and said he was worried about if the children throw something at it? 
TBH, I hadn't even thought about risks with using one. I wanted to let in more light...and replace the shabby old thing that hung there previously!
My children don't ( as a rule) throw things...Are they considered safe these days? bearing in mind its no longer the dangerous '70's style door of my youth? 
oh, and its just half of the door...