It can accidental damage to the lens and also fingers from accidentally touching the surfaces of the lens. The ET67 Lens Shade is to effectively block strays light and reduce unwanted lights,enhancing your photos. During forward and side light photography, scattered light from the surrounding area can be avoided from entering the lens. From durability ABS this Lens Shade effectively blocking scattered light, the light shielding covering internal extinction treatments. When taking photos with backlighting, side lighting,it can not imaging light from entering and avoid fog.