One of my biggest issues with my pistol is that besides being cross eyed dominant, I also have both terrible nearsightedness and farsightedness. -5/+2.75 . Highly astigmatic as well. So while they tell you not to try to focus on both sights, I can barely see one. I have progressive lenses, and have to move my head to get me looking through the right part of my glasses to see the sight.
For those who might have the same issue and have used a RDS, would a RDS help? I use a RDS with my rifle with no issues at all.
I'm nearing 60. I wear progressive contacts. Your nearsightedness is nothing. I'm around -11 on both eyes.
I have a hard time focusing on the front sight, particularly in low light. For competition use, my optician made up some shooting glasses to wear over my contacts with my left eye having no correction and my right eye being a +1 reading lens. This lets me see both the target and the front sight and works well for games. Not so much for defensive purposes -- "hold on there robber while I put on my reading glasses..."
The RDS is focused at infinity, just like the target. You focus on the target and you see the red dot overlaid upon it, while keeping both eyes open. So the RDS helps those of us who can't easily focus on close objects like a front sight.
However, RDS comes with its own disadvantages. They are expensive. They are bulky. They require batteries that need regular replacement. They take more practice to use quickly at close distances -- otherwise you end up searching for the dot.
I'm trying to spend about 15 minutes several times per week in the basement doing dryfire. I start with the gun already drawn, held in both hands, compressed to my chest, then extend to the target, find the dot, and press the trigger. Then I start drawing from my holster. I'm hoping this will speed up my ability to draw the gun with the red dot in view. Sadly, Glocks don't point naturally for me, so that is working against me. In a free state, I might play with other options than my Glock 19.
If you're not willing to do a bunch of practice, then the RDS may not be for you.
Other alternatives are 1) learn to point shoot at closer distances (use target focus rather than sight focus) or 2) laser sight (which also requires batteries and will also require new holsters).