The Slate Reader CollectionThe Slate Eco-Sustainable Blue Light Reader will keep eye strain and fatigue at bay with our premium blue light filtering lenses. Our Blue Planet Blue Light Filtering Glasses are available in standard reading strengths 1.25, 1.50, 1.75, 2.00, 2.25, 2.50 & 3.00, including no correction 0.00. The lenses are built with Blue Light protective technology to prevent eye strain and other harmful effects from the light emitted by digital screens by filtering 40% or more blue light rays emitted by digital devices. Specs Lens Width (mm): 52 Bridge Width (mm): 22 Temple Length (mm): 148Lens: Premium Blue Light Filtering Reader (0.00-3.00)Material: Hand polished ultra-lightweight eco-friendly frames are made with our very own Eco-Process which reuses 60-75% recycled & reprocessed content that would otherwise end up in landfills or our oceans.