Whether you want to learn to scuba dive, or you've already been diving for a while, there's a good chance you wear prescription lenses. (Over 194 million adults in the U.S. wear corrective lenses according to The Vision Council's VisionWatch 2018 Annual Report). Do you need to ask your optometrist for another prescription before you buy corrective lenses for your diving mask? The short answer is: no. Read on for important details on how to order the correct lenses for diving.
Corrective diving lenses follow the same diopter numerical system used for eyeglasses, so you'll need to know what your current prescription is, but you need to adjust that number when you order lenses for your diving mask. This compensates for the slight magnification effect of seeing underwater (versus seeing normally through air). You'll want to adjust the number to be ±0.5 closer to zero than your current prescription.
If you wear -3.00 on your eyeglasses, then you would choose a -2.50 lens for your diving mask.
If you wear +3.00 on your eyeglasses, then you would choose a +2.50 lens for your diving mask.
If each eye has a different prescription, you would make a + or - 0.5 adjustment to each lens.
If you're looking for good optical lenses for your diving mask, check out IST's Pro Line OL-80 Corrective Lenses. They're compatible with 3 of our most popular diving masks: M200 Synthesis, M80 Search, and ME80 Pro Ear Mask.
We also carry bifocal diving mask lenses.