Do far sighted people need a prescription dive mask?
Unless you want to look at things real close, you may not need a sprecription mask if you are far sighted.
Prescription Dive Masks
I am short sighted, do I need a prescription mask?
If you are looking at close things only, you may not need a prescription mask, and through the water you may even gain half a precription strength. To see things in the distance however, you may have to use optial lenses.
Can prescription lenses be fitted to a dive mask?
Yes, they can. Some masks come with with factory fitted optical lenses. Some high end dive masks will allow you to fit two different strengths of optical lenses.