California Prop 65
Glasses and sunglasses may display the Prop 65 warning because of the Bisphenol-A (BpA) found in polycarbonate lenses. Bisphenol-A (BpA) is a starting material in the manufacture of polycarbonate, so there are trace amounts of BpA found in those lenses. Common consumer goods, such as water bottles and the coatings on the inside of many food and beverages are made with BpA. According to www.factsaboutbpa.org, studies have consistently shown that the potential migration of BpA into food is extremely low, generally less than 5 parts per billion. Also consider that you will not be biting, drinking from, or otherwise ingesting the lenses of your glasses. In May, 2015, the state of California relisted (BpA) on the Prop 65 chemicals list.
⚠️WARNING: Cancer and Reproductive Harm - WWW.P65warnings.ca.gov