Here's the thing with prescription masks and high correction. Please note everything I am saying applies to being farsighted/hyperopia at >+6.5. Maybe this is another area where nearsighted folks get an advantage over us hyperotics.
At scuba mask size the lenses are THICK. If someone will make your prescription in high index, last I checked SV was still using cr39, it is thinner, not thin, but now it's heavy. Dead center the vision is great. Off center the distortion is horrible, nausea inducing, gets worse the further off center you get. Your peripheral vision becomes non-existent. This problem is magnified 10X when night diving. Using contacts resolves all of this.