Welding can be very damaging to your eyes if the proper filter is not used.  When welding, there are three kinds of wave energies that you must protect against: ultraviolet (UV), infrared (IR), and visible light. UV and IR are invisible yet very harmful to the eye, and standard green IR lenses block them. Our Super Blue Drop-In filter is a blue polycarbonate lens that blocks the yellow/orange line of the visible spectrum (589-600nm) and is designed to be used with your standard green welding lens. This filter improves your clarity of vision by greatly reducing the brightness of the arc and eliminating yellow flare.The Super Blue lens is to be used ONLY in addition to your standard welding shade. The filter lens will add about 1/2 of a shade, so you can use your normal lens with it.DO NOT USE THIS LENS BY ITSELF!!! PERMANENT EYE DAMAGE CAN AND MOST LIKELY WILL OCCUR IF USED ALONE!!!Help protect your eyes while working.  Should you have any questions please call our friendly and helpful customer service reps at 866-575-1307.Jessica