Been re- thinking things recently.
A good number of shooters, that wear Glasses, or have a stigmatism cannot get on with red dots, they get a glaring dot.
Many red dots can also shift theres zero. …without you having shifted it.
The reason for the zero shift is due to the tiny LED being epoxied onto a small slide which gets moved by the elevation and windage screws to re-position the point of light onto the main lens..
Tiny variations of movement from recoil potentially shifting impact.
I recently set up a ghost ring. These work as an aperture sight, allowing a much more focussed view of the foresight and target for the failing eyes..
Aperture sights are mainly intended for rifles, but with a larger aperture, they work fine on pistols…
Give one a go if you are struggling to focus …you would be surprised by the results..
I also have pretty bad astigmatism, red dots usually look like a sunburst with a lot of vertical spread. This is apparently due to the way astigmatisms bends light off center in the eye. For a lot of astigmatism sufferers, if you put an aperture between your eye and the red dot, the dot will sharpen. I have thought about putting a cheap flip-up AR rear sight behind my red dot to flip up when I want a more precise shot.
What you require is one of these new Ghost ring rear sights.
Ive had a try with one, which sharpened everything up.
There is none of the red dot blurring issues, or shifting in point of impact due to slight parallax errors, or the LED shifting due to the recoil…