When evaluating lens quality, focus on the optical glass material; high-quality lenses use multi-coated lanthanide glass to reduce flare and ghosting. Pay attention to the magnification power (e.g., 2x for telephoto, 0.6x for wide-angle) and distortion rates—professional-grade wide-angle lenses should have less than 1% distortion. Additionally, verify the mounting mechanism, ensuring compatibility with the latest iPhone models via 17mm thread mounts or dedicated phone cases for maximum stability.