alwaysuv blue light shield computer reading/gaming glasses for kids anti blue light 90% uv protection low color distortion green frame alwaysuv <br><b>features</b> <br>material: plastic <br>lens: this glasses transparent lens<br>frame: a stylish, compact and lightweight retro classic full frame design <br>color:black, blue, green, purple, blue pink <br>package include: 1 x glass <br><b>blue light blocking</b> <br>if you are unfamiliar with blue light it's right next to uv light on the spectrum of light. it is comprised of very high energy and a low wavelength very similarly to uv light. all of our electronic devices with a back-lit screen give off large quantities of blue light (iphones, ipod, laptop, computer tv.) <br>this blue light messes with our internal clock making us think it's mid day when really it can be closer to night and stops our body from naturally producing the melanin that helps us fall asleep late at night. <br><b>measurements</b> <br>lens width: 46mm <br>lens height: 37mm <br>nose bridge: 15mm <br>arm:133mm <br><b>cleaning: </b> <br>1. the glasses should be treated carefully to avoid damage and should be cleaned regularly <br>2. clean the lens using soap water or neutral detergent, gently wipe dry with the soft glasses cloth