My eye power has changed 0.5 since a year (2018-2019) in both eyes. my age is 25 and doc told me im suitable for prk/lasik. before a week i went through prk. my vision is clear now.will i get eye numbers again in future above 0.5?how to prevent it?

Maybe. Maybe not.: To answer that question, a person would have to know whether or not his vision would become more nearsighted (or more farsighted) during the years between age 25 and 40, if he had not done the LASIK. How would he know that? We can clearly see the present, but how can we see the future? That said, it is probably not preventable because one's eyeball's tiny changes are not controllable.