I have read good advice from many sources that say concentrate on a front sight post that is in focus and don't worry about the target being fuzzy. Of course small peep apertures help make the target less fuzzy. But for Red Dots I wear glasses that make the target in perfect focus. Now all I have to do is put a 2 MOA red dot in the center. I have a expensive Sig Sauer red dot and only recently acquired glasses for distance. I can now hit targets just as well as my peep sight rifles if I concentrate on the target and red dot on POI. I have renewed interest in Red Dots with very small diameter light.