CLEAR. Crews rocks the industry with the launch of the aspheric safety lens. Crews' exclusive Carbon Cut Technology™ applies lessons learned from premium optical industries in producing one of the most important technical advances in safety spectacles. Crews' aspheric safety lens resolves employee complaints of headache and distortion. An estimated 35 percent of PPE users currently wear safety glasses that do not provide a proper optical fit. The problem is P.D. or interpupillary distance. Safety glasses utilizing traditional technology can only provide an optimum optical center in a small area of the lens. If a user should fall outside the optimum range due to his or her P.D., the user could experience optical discomfort. The TRIWEAR® and TRIWEAR® METAL safety glasses feature the widest optically correct viewing zone, providing a superior fit for virtually every user. Please view the charts below for a visual representation of the different interpupillary distances.