I have astigmatism and wear corrective lenses.
Personal experience only, having used them, taught dozens of shooters, and competed for almost ten years across four states:
Some people like them. I loathe them. Dangerous game “express” sights work on a rifle because of the sight radius. Shotgun beads working on shotguns because of the sight radius. Those principles do not translate to a handgun. I have found them to be as useful as removing the rear sight.
If you have not tried a bright front sight (fiber optic or Trijicon XR) paired with a plain black, wide-notch rear, I highly recommend it. You’ll gain lots of front sight visibility, generous light bars for confirming alignment at speed, and the ability to make precise shots as needed. I wear corrective lenses and have astigmatism in both eyes. That set-up is what I have found to work best.
I found that the biggest detriment to Big Dots is they inculcate sloppy muscle memory. There’s not enough relationship between the front and rear sights to confirm a “perfect” sight picture. So, you lose out on the ability to train pure marksmanship (e.g. B8s at 25 yards). That type of shooting is critical for reinforcing the muscle memory of proper sight alignment—necessary to shoot a handgun target-focused or in low light.