This isn’t true? Myopia develops rapidly in youth then stabilizes in adulthood. It gets a worse with age, not corrective lenses. Then sometime after 40 you flip to presbyopia when your lenses lose flexibility.
Don't trust everything your doctor says verbatim, they often oversimplify and their information can be out of date. Give your doctor the benefit of the doubt but check it against other sources and use it to build a mental model.