Why does my child need to wear Sunglasses? Baby Banz are a necessity to cover infant and toddler eyes from the harmful rays of UV (ultra violet) light. Until approx 8-9 yrs old a child has no filters in the eye to block out UV light. You can actually do MORE harm to the eye if you put an inferior lens in front of the eye! Behind tinted lenses, the iris opens to allow more light into the eye; if the lens doesn’t protect properly, and more UV light gets into the eye potentially damaging the child’s eye. What is the UV protection of Baby Banz and Kidz Banz? The lenses are a UV400 lens. These lenses block out the entire spectrum of UVA, UVB, and UVC rays from the sun. UVA rays are thought to be more harmful to the skin – they cause sunburn and get below the outer layer of skin. UVB rays are the rays thought to be the worst on the eye and causing damage to the retina and lens with overexposure and under-protection. UVC rays are extremely dangerous but do not reach the earth's surface due to absorption in the atmosphere.What are the Sunglasses made from? Baby Banz frames and lenses made from polycarbonate material. This material makes Baby Banz virtually shatterproof and ensures that they stand up to wear and tear.