MLeake:
A whole paper could be written on pistol sights. First, sight alingment and trigger control must happen simultaneously and the eyes should stay focused on the sights: the target should blurr somewhat. Here's why that you shouldn't switch your eyes focus from the sights to the target. The target, in most cases, is stationary. The hits on target will still be there after the string of fire is over. Switching the eyes to the target blurrs the shight and a misalignment occurs. if you're seeing the target clear, you won't shoot a good score. When I was shooting on several Marine Corps' pistol teams, I blackened my sights to prevent glare. There's some argumant that you should focus on the front sight or to focus on the rear sight. I'm not sure witch is best. I focused on the 1911's firing pin and I got excellent results.
I would suspect that the three dot sights help some shooters focus their eyes on the sight where they belong.
Gunnery sergeant
Clifford L. Hughes
USMC Retired