What is Blue Light Blue light has a short wavelength and is likely to scatter, causing fatigue of the ciliary muscles, which are the adjusting muscles that adjust the lens, and may cause eye strain. Blue light can cause a wide range of risks including eye strain, sleep disorders, damage to the retina, dry eyes, stiff shoulders, and headaches. For those who operate smartphones and PCs or watch TV, it is recommended to take measures immediately with blue light blocking glasses. SIGVAN blue light blocking glasses High manufacturing quality, material lightweight and durability. Metal spring hinges help glasses adapt to face,built-in stainless. Convenient Set of 5 means you'll have a pair handy wherever you are. Keep a pair in your favorite reading spots. Clear lens,No affect reading, and almost no color difference. Package includes: 5 x blue light blocking Reading Glasses Eyeglass Pouch Cleaning cloth Size: Lens width: 52mm/2.04in Lens height: 38mm/1.49in Bridge:20mm/0.78in Arm: 140mm/5.51in Frame width: 135mm/5.31in Material:Plastic, which has the characteristics of super lightness, abrasion resistance low friction coefficient and so on. If you have any problems with our items or services, please feel free to contact us. We will do our best to solve any problems and provide you with the best customer services. Thank you so much for support us!