Never, ever take a head shot in spite of what all the other posters have said on this site. The head is too small a target and if you hit the animal in the jaw he will run away and die a very slow and painful death.
Hmmmm...... you almost Never say Never or Always, number 1.
If you can't MAKE the shot, don't take it. This goes for ANY zone. If you can't HIT heart/lung at 500 yards, frikken don't shoot. If you can't hit a head at 100 yards, don't frikken shoot. It's that simple. KNOW YOUR LIMITS.
You owe it to your quarry to use more ethical shot, a shot that is much easier to undertake and that is a heart lung shot.
I've seen way more deer go off wounded, gut shot, from someone trying to hit the heart/lung than I have missed head shots. I agree... you owe it to the animal to make an effective shot. But what's an easy obtainable shot for you may or may not be for the next person.
If you can not get in a clear shot through the lights well, he got away pure and simple.
Lights? Hmmm.... we call the eyes "lights". Hence the term lights out. So I'm a bit confused, but it would seem you are advocating a heart/lung shot so I will take it in that context. You have way more chance of them NOT getting away pure and simple when shooting the center mass area than if you are shooting at the head. 6" high or low on a head shot and they should run off into the sunset. 6" high or low on a heart/lung shot and you have a wounded deer that will die slowly.
Those that advocate a head shot should be allowed to only have plastic guns and rubber bullets
Maybe those that aren't good enough shots to HIT a smaller target like that should be the ones only allowed to have plastic guns and rubber bullets. I'd much rather have a real gun in the hands of a marksman than in the hands of someone that can't hit the broad side of the barn from the inside.