What if you are not a naked-eye match for a Double-Dome mask, and you cannot wear contact lenses for medical reasons? But you still want the very best in underwater vision. HydroOptix's proprietary technology lets you enjoy the best possible vision through a flat-front lens. - Your EXACT prescription Pupiliary Distance (PD), Astigmatism Correction, Prism, etc. - Bifocal prescriptions available - Super-comfortable silicone face-skirt - Wide choice of frame colors and purge valve option - Color-correcting lenses at no additional cost (pink / yellow) for mild prescriptions - 100% made in USA