GetWetStore RX Scuba Dive Snorkeling Mask Prescription Lenses ProMate Scope Scuba Dive Mask (MK245) and tempered corrective lens (OP250 and 251) 100% silicone skirt and facial profile design make comfortable fit Nearsight Optical correction lenses available from -1.0 to -10.0 by increments of 0.5. Farsight Optical correction lenses available from +1.0 to +4.0 by increments of 0.5. Bifocal Optical correction lenses, also called Gauge Reader available in +1.0, +1.5, +1.75, +2.0, +2.25, +2.5, +2.75, +3.0, +3.5, +4.0.