Polycarbonate lens REDUCE DIGITAL EYE STRAIN - 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, Enjoy a restful deeper sleep. MATERIAL - Frame: TR90 ; Lens: Polycarbonate (Non-Prescription) 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. The symptoms of digital eyestrain Headaches, sore or tired eyes, and stiff necks are all symptoms of digital eyestrain. Spending the majority of our waking hours in front of device screens put our eyes through a lot of wear and tear. At the same time, Blue light from our computers, phones, and tablets causes our eyes to not only work harder but puts them at risk of aging faster. Let we protect your eyes! Our glasses are specially designed to filter out a portion of harmful blue light. The premium features of lenses, make screen time more comfortable and help eliminate symptoms of digital eyestrain.