The EN 166 standard is the European benchmark for personal eye protection. When sourcing, you must verify the optical class (Class 1 for permanent wear) and the mechanical strength rating. For example, 'S' denotes increased robustness, while 'F', 'B', and 'A' represent different levels of high-speed particle impact resistance. Additionally, ensure the goggles meet Field of Use requirements, such as 3 (liquids/droplets), 4 (large dust particles), or 5 (gas and fine dust) depending on your specific industrial application.