LensCovers are designed to fit over prescription frames, a practical alternative to expensive prescription sunglasses! In addition, LensCovers wrap around your face blocking the sun from all sides. For proper fit over prescription, go to the sizing image for measuring of prescription frames to match your size of LensCovers. LensCovers provide 100% UVA and UVB protection and are polarized, providing increased clarity, reduced eye fatigue, and glare protection.