How to maintain decent vision while wearing my glasses?

No clear answer: The question as it is asked is unclear in its meaning. At one end, take good care of your glasses by keep keeping them clean, scratch free and in adjustment. At the other end, no matter what you do short of dying too soon, you will eventually need bifocals to see up close if you can see clearly off at a distance. Glasses will not make your eyes weaker; getting older will.