I had both my cataracts replaced a few years ago. I shoot pistol right handed (due to a knackered left elbow) and rifle left handed. I dont seem to have any trouble shooting pistol with Ready Read glasses I bought from my local Pound Store ( or equivalent). I also manage to shoot rifle but mainly use scoped rifles as I to struggle to focus on the sights and the target. May I suggest a visit to your local Pound shop (without the guns of course )
HTH
Ian