Material:Alloy,Resin Size:Spectacle lenses 32*39mm,Nose spacing 19mm,Length of glasses 130mm Strength Power for optional:+100,+150,+200,+250,+300,+350,+400 Eyewear Type:Reading Glasses Blue Light Blocking Glasses protect your eyes from harmful blue rays,electromagnetic wave radiation,and UV glare.For those who face computers,laptops or smartphones all day,these glasses are essential for the eyes. These glasses effectively block 90% of blue rays,reduce eye strain and other visual syndromes (blurry visions,bulging,headache,dry eye,declined visions,etc.). Made with resin lenses,these blue light glasses are ultra-lightweight and comfortable to wear for men and women.You won't feel heavy on your nose when playing games,surfing the Internet,or working on your laptop for hours. By wearing blue light blocking glasses,you can avoid eye fatigue,dizzy head,headache,etc,and therefore have a better sleep at the end of the day after a long time staring at digital screens. The lightweight glasses means you'll have a pair handy wherever you are.  Package Included:1 Pc Reading Glasses with Case Notice: 1. Please allow 2-3% error due to manual measurement. Please make sure you do not mind before you bid. 2. The colors may have different as the difference display,please understand.