GetWetStore NearSighted Prescription Optical Lense (Piece) Snorkeling Diving Masks NearSight Prescription / Corrective Lense (Piece) for Snorkeling and Scuba Diving Mask: highest quality optical raw glass. CAD & CAM MOLD, full view designed, and precisely ground and finished. Tempered Glass. performances meet ANSI Z86.11-1985