While I was working at Intel, the company implemented a policy that all doors must have eye-level windows. I watched carpenters modify doors in accordance with this policy, and I think it's a good idea. If you can always see into a room, there's less chance it will be used for robbery, espionage, chicanery, sexual quickies or sexual harassment. But I must admit, I remember seeing few truly beautiful doors with big, eye-level windows in them.
I was reminded of that last night, when I approached one of the nicer buildings on our local university campus. I faced a pair of giant, windowless doors. Their beautifully finished wood glowed in the light of a nearby red LED sign. I was about to step up to these doors and open them, but an undergrad was quickly catching up to me, so I stepped aside to let him have the honor. As he did so, the doors opened smartly from within, clobbering the undergrad and knocking him down.
Doors with Windows ... a word to the wise.