We have in stock, +1.75, +2.25, and +2.75 for divers who want to be able to clearly read their gauges. Please do not mistake these pre-cut lens as add-on lens. They are pre-ground and inserted into your mask in place of the standard flat lens.
Please note that these lens are for those divers who only require lens for reading their gauges (similar to reading glasses). The top portion of the pre-cut bifocal lens is plain glass and the bottom half can have a diopter anywhere from +1.75 to +2.75 in 0.5 diopter increments.
Beyond that, we also offer lenses for divers who are near-sighted and require negative diopter full lens ranging from -1.5 to -8.0 in 0.5 diopter increments. For negative lens with a full pre-cut lens from top to bottom, please inquire about these particular lens or see them in our other listings.
To determine the proper prescription lens needed, simply start by looking at the second number (cylindrical) of your prescription and see if it is equal to or greater than "1.0" (+ or -). If it is greater, then cut that figure in half and algebraically add it to the first number (spherical). If the cylindrical is less than "1.0" (+ or -), you can ignore it.
Since the final figure may fall somewhere in between the pre-ground lens, simply round off to the nearest diopter.
If all of this sounds too complicated...don't worry, just call us at 818-913-3359 or email to firstname.lastname@example.org. Upon request, we will contact you via telephone to verify your prescription prior to lens installation and to answer any questions you may have.