It has been said that "The eyes are the window to the soul" but, once you get into the boxing ring, they can also be the key to the fight.
Look deep enough and a fighter's eyes can tell more of the story than just whether he's scared or not and they can play a larger role than just being an intimidation factor during the pre-fight stare down. Whether that pre-fight ritual has any real bearing on how the fight plays out is up for debate, but looking into your opponents eyes during the course of the contest can be extremely telling.
A fighter can sometimes appear confident on the surface. He may appear composed and in control...that is, until you connect with a good shot, then his eyes may tell a different story. Your opponent's body can sometimes hide clues that the eyes just can't conceal.
In the course of a fight, if you only take your cues from how his body acts and reacts, you may miss an opportunity. His physical demeanor may not display moments of uncertainty, when he's trying to mount an offensive attack or frustration, when he can't seem to connect with his combination, but his eyes will likely betray him. On the surface, he may appear to be physically strong, but peering deeper you may be able to see signs of fatigue or concern about expending too much energy.
The most obvious way your opponent's eyes can betray him is when he is hurt. He can wave you forward after taking a solid punch, but his eyes may tip you off to the fact that, in spite of his show of bravado, you hurt him. Some fighters can put up a good front, but there's no hiding the moment, however brief, when you expose that weakness. It may not be an obvious look of pain, but could show up as a sudden lack of focus, fear, uncertainty or could just be a blank stare. Regardless of the message, what his eyes tell you could determine what your next move is, whether you should turn up the heat or remain conservative.
The eyes can also be used for deception. You can use your focus to divert your opponent’s attention and make him think you are going to throw a specific punch. For example, you could look at his body and throw a body shot. Then look at his body again and throw another body shot. Convince him think that you are looking at the spot you're going to throw at before you throw. If it looks like he has caught on to your habit, look at the same spot and instead of throwing that body shot, bring that same punch over the top where he's likely left himself open. Using your eyes to divert your opponent's attention or throw him off is like a fake or a feint without having to expend any more energy. It all happens with the eyes.
Looking into your opponent’s eyes, can tell you a lot about him, before or during the fight. You may see a weakness from the start, gradually gauge how he is reacting to your attack as the fight progresses or, based on what his eyes tell you, sense when it's time to close the show. Having the added sensibility to look deeper than what your opponent is letting you see on the surface, can add another dimension to your game. Treat your opponent's eyes as the window to his soul and it may open the door to a new world of opportunities in the ring.