You should remember those military sight you refer to are designed for young people, with at least 20/20 vision. Theodore Roosevelt was a great shooter, with a lifelong battle with poor eyesight. He also had enough disposable income, to devote an emmence amount of time and money to finding the sight combination the worked for those with poor eyesight. He recommended a rear sight with a gradual V leading to a round bottomed notch. The front sight was a bright metal, or ivory, barley corn sight that perfectly fit the notch in the rear sight, with little or no room for light on the sides. The gradual V forces your eyes to sharpen their focus. A sight shade even improves on this system if your shooting discipline allows it.
Hungry Horse