D&D Monster Study Proves Eyes Have It
sciencehabit writes with this excerpt from Science: "The dungeon is pitch black — until the dungeon master blazes a torch, confirming your worst fears. A Beholder monster lurches at you, its eyeballs wriggling on tentacular stems. As you prepare to wield your Vorpal sword, where do you focus your gaze: at the monster's head or at its tentacle eyes? Such a quandary from the role-playing game Dungeons & Dragons may seem like a meaningless trifle, but it holds within it the answer to a tricky scientific question: Do people focus their gaze on another person's eyes or on the center of the head? In fact, a father-son team has used D&D monsters to show that most people will look to another creature's eyes, even if they're not attached to a head."
I don't watch at eyes, I watch at boobs amirite?
Those tits certainly have the look.
It has been shown many times in studies that people are able to read a lot of emotion by looking at another person's eyes. Looking at foreheads doesn't give you a tactical advantage, but if you can look in someone's eyes you can see what they are feeling most of the time. You can also see where they are looking, and where their attention is at, which is critical. Of course, good magicians know this and look at the wrong things at the wrong times to mislead you ;)
Just because I can hook a shark from a boat, I do no offer to wrestle it in the water.
Makes sense. There's a survival advantage whether you're predator or prey, it doesn't matter if you can see it, it's whether or not it can see you. Being able to see its head, claws, or gelsacs is useful, but the thing that gives you a survival advantage is knowing whether or not it can see you. If you can see its eyes, it can see you. (The converse - if you can't see its eyes, it can't see you - does not hold unless you're a Ravenous Bugblatter Beast of Traal.)
Car Analogy: Same as if you're driving on the highway past an 18-wheeler. If I can see the trucker's eyes in the side mirrors, he can see me. (I'll assume he can't for the sake of prudence, but it's possible he can see me). If I can't see his eyes in the side mirrors, it's my responsibility to position me vehicle in such a way that he can see me, and/or somewhere he can't hit me whether he can see me or not.
Always look at your opponents eyes, (if they're not highly skilled) they will usually look at an area before making a move in that direction.
"Kill 'em all and let Root sort 'em out"