A friend of mine who can really shoot (He is both a Distinguished Marksman and Distinguished Pistol Shot) recently had laser surgery on his eyeballs, and after I complemented him on his new, glassesless self, we got into a discussion on aiming with iron sights.

“One of the things I’ve learned,” he said, “is that if you take a deep breath and let most of it out, you’ve got about 7 seconds’ worth of oxygen to press the trigger. Take longer than that and your sight picture will start to blur, because the first thing that goes when your brain isn’t getting enough oxygen is your vision. If you do blur, take a couple of deep breaths and start again.”

A couple of days later, I was giving some shooting instruction to a couple of beginning shooters, and one complained that her eyes were blurring. “Take a couple of deep breaths,” I said.

Damned if it didn’t work.

The second tip is for handgunners, from the same source. If you’re not thoroughly hydrated and you do any amount of handgun shooting, your hand will swell to the point where it becomes a problem. And you can’t guzzle a quart of water before you step to the firing line; you have to get it into your system 24 hours beforehand.

“You end up with a full bladder all night long,” my amigo says, “but it works.”

Having seen him shoot, I believe him.