Serengeti NorciaSatin Black/Black / Polarised 555nm LensesNorcia by Serengeti has a double injected stainless steel frame and elastomer temples. The adjustable nose pads provide the best fit for a broad range of face shapes too.Serengeti's 555 lens manages yellows and greens to help relax the eye. A slight silver mirror coating helps reduce glare. It's perfect for bright light conditions. It's polarised too so reflected glare is beaten.Serengeti's patented Spectral Control fine tunes light transmission so your eyes get the best clarity and colours available. Spectral Control also helps block most blue light – damaging to eyes and a cause of eye fatigue.And the photochromic lenses lighten and darken with the conditions, even inside the car where UV is minimal. Lenses are of glass, are UV400 and Norcia also comes with a one year manufacturer's warranty.