Protect your eyes in style with these Swanwick® Crystal Day Swannies. These are blue light blocking glasses that can be worn all day, every day. Wear them whenever you are using digital devices to protect your eyes against harmful blue light and eliminate the symptoms of digital eye strain, including dry, sore eyes and headaches. With CR-39 lenses, Crystal Day Swannies provides you with the perfect balance of protection. While it blocks harmful blue light, it still lets some of the healthy blue light (450-500nm) in to help for regular circadian rhythm and improved alertness and memory function. These glasses come with cellulose acetate frames, making them adjustable, strong, and lightweight.