When you raise your pistol to the target do you instinctively close one eye to line up the sights? Don't. Starting today, right now, begin teaching yourself to shoot with both eyes open. Here is why. Closing one eye severely compromises peripheral vision. Closing one eye cuts that down by some 40 percent. Add on the stress of a deadly force encounter and you will most likely experience vaso-constriction resulting in at least some level of tunnel vision. You will be focused on the threat so intently other items in your field of vision will be out of focus…. and that field is already reduced because your one eye is closed. The end result is you might end up losing half of your peripheral vision! That means you could miss seeing an additional threat or misidentify a friendly or innocent bystander. You need all your vision. Here is how to make it work.First, identify your dominant eye. To do so, extend your arms with your hands together, palms facing away from you to make a 1 inch triangle with your hand through which to look. Keeping both eyes open focus on an abject some distance away and slowly draw your hands back toward your face. Keep both eyes open and keep the object centered in the triangle. As your hands get close to your face the triangle will automatically come in front of your dominant eye.If you shoot with your right hand and your triangle ended up over your right eye… or vice versa… you win. All you have to do make an effort to keep both eyes open though dry-fire and live-fire training. You can do this.If, like me, the triangle falls on the eye opposite your shooting hand, you have some adjustments to make. You can take up shooting with your other hand or you can turn your head a bit and aim with your left eye while shooting with your right eye. You are losing a little bit of vision to your left side, but not as much as if you closed your left eye and shot with your right.A third option is retrain your eyes so your dominant eye matches your dominant hand. Put translucent tape over the off side lens of your shooting glasses and aim naturally with both eyes open. I failed miserably at trying this. My lef eye did nothing but water as it strained to focus on something. I finally gave up. But it works for some.Sit down and figure this out. It's the right thing to do.