Ravenger, what does VDU stand for?
Visual Display Unit, or more colloquially, a computer screen.
I know this is a little old, but look for information from competition shooting on getting this sort of lens made. Not many doctors deal regularly in distance vision other than infinity.
Here's a good guide on getting your doctor to write a prescription for exactly the lens you need.
I know this is old, but a tweet from John Carmack: