alba optics delta vzum%E2%84%A2 alensDELTA uses VZUM A LENS made from scratch resistant polycarbonate, with a non centred base 6 that enables fixed vision without side view distortion. The curve covers an optical cone of 180, providing excellent protection against the wind and strong light, that often reflects on other sunglasses creating an eye blinding effect. The shock absorbent, unbreakable material provides excellent resilience. FEATURES Ventilated VZUM lens Interchangeable VZUM