Specifically designed for narrow faces, these Slip sunglasses have a lens tint to accommodate you. Carbon frames feature Fototec lenses that automatically adjust tint according to light conditions lenses darken in bright light and lighten when theres less light. . Iron frames includes 3 sets of lenses allowing you to interchangeable the lenses depending on the light conditions. . Lenses are ideal for low- and medium- light to night time conditions. Lightweight and virtually shatterproof, polycarbonate lenses are 20 times more impact resistant than glass and one-third the weight. Grilamid TR90 lightweight nylon frames offer a consistent fit and flexibility in all temperatures and are extremely impact resistant. Hydrophilic rubber nosepiece and temple ends become tackier when wet for reliable grip during exercise and hot weather. Ventilated lenses increase airflow to help eliminate fogging. Fits small to large faces.