I can't answer the questions in terms of its impact on a flying career, but I think your definition is wrong.
Shortsightedness/nearsightedness (myopia) is the inability to see clearly things which are far from us. Thus we need correction for driving, cinema, etc.
As we get older, the condition which normally sets in is the opposite, longsightedness/farsightedness (hyperopia), which means we need correction to see things close to us, such as books, the computer screen, but can see distant objects clearly.
As I went through my forties, I wondered why the print on labels, in magazines, and so on got smaller and smaller.