Does wearing eye glasses after becoming 近视 help preventing further deteriioation?
Wearing eye glasses is certainly an environmetal factor not a genetic factor.

In China, there used to be a time parents did not
try to geta pair of glasses in time for kids
(one reason could be parents could not afford).

In USA, if parents do not do that in time,schools
can inform governments because it is considered
as mistreatment of childrens.