With a good peep sight all comes into focus. Get a good front sight too, like a lyman 17.
https://www.opticsplanet.com/lyman-57sml-and-57gpr-receiver-sights.html
Open sights will not work well as we age. IF you must use them, get glasses made that focus the top of the bifocal at about 4'. Forget about progressive lenses, they are useless for shooting. The front sight is the important thing to focus, the target is suppose to be blurry. Switching focus between the sight and target is not the best way. As we age it becomes impossible. Focus on the front sight, squeeze, follow through. Success will follow