For a long time i needed single vision lenses as i had not only myopia but also a axial curvature of the eyes (i hope this is the correct english term).
I let my optician glue "my" glasses in the mask. Getting slowly older also my near vision also got worse and with the axial curvature i went back and got some special varifocal / multifocal lenses glued in a new mask.
If you have a low volume / kind of freediving mask this can be a problem as the glued in glasses can get too short to the eye that your eyelashes have contact with evera eye closing (made me crazy...), but with a regular diving mask the "made to measure" glasses are the best, especially if your curvature is not correct.
There are also variofocal/multifocal contact lenses available, but i would try to use a bigger mask and special multifocal lenses which also correct your distance vision (which might be off as well). It surely will help your vision, you might check with a good optician.
Hey Gerard! Nice to see you switched over, too 🙂
