I had this issue until I got a 2nd prescription by a different provider and new lenses. Sometimes lense material etc also matters. Bigger PITA than I thought getting glasses was going to be.
Lens material absolutely matters. Glasses suffer from chromatic aberration, and this causes visible rainbows away from the center of the lens. A material with a higher Abbe number will perform better.
For common lens materials, polycarbonate has a low Abbe number, and Trivex is a widely available alternative with a higher Abbe number. You can find tables online for common lens materials.
Nearsighted, left eye worse.