RX Prescription Lenses for the Promate Hawk Eyes Mask Series - Optical Lens(Bi focal-Gauge Reader and Near Sighted) Prescription mask available: Item Code MSK131 & MSK131A Please note there will be an additional 2 to 3 days processing time for most RX lenses Cost is per single lens only Ultra low volume Extra wide and long lenses provide wider peripheral view and downward vision Tempered glasses Optical lenses available from -1.5 to -8.0 by increments of 0.5 (for nearsighted/myopic) Bifocal lenses available for +1.75, +2.25, and +2.75 (gauge reader bi-focal lenses are a non-prescription lens with a small reader prescription) Returns are not accepted for used lens. Only unused lens are eligible for return with store credit.