Polycarbonate lens REDUCE EYESTRAIN - Enjoy your digital time, NO worry about eye fatigue, blurred vision and headache. ANTI BLUE LIGHT - Cut 90% of the blue light. Relieving eye fatigue, dry and vision falling. BETTER SLEEP - Reduce eye strain and headache, so you can enjoy a restful deeper sleep. MATERIAL - Frame: TR90 ; Lens: Polycarbonate (non-magnification) LIFETIME WARRANTY--We provide worry-free lifetime warranty and friendly customer service. Why do we need to filter blue light? The main source of blue light in our lives is the harmful blue-violet light emitted by our digital screens. From TVs to tablets, and computers to phones, were constantly exposing ourselves to unnatural blue light. By wearing blue light blocking glasses, you can limit the amount of blue light that enters your eyes and make your screentime more pleasant.