I used Seavison in San Diego.
They did a great job; distance correction upper, plain glass lower.
Find a mask with tall lenses (e.g. Scubapro Spectra) to give more real estate.
I also had them bevel the lower edge of the upper corrective part, so looking downwards I am looking along the bevel, rather than across a flat, distorted transition. It gives the impression of no correction and makes more of the surface useful for vision.
- diver21 likes this