Maybe it will inherit to your child. But no must. In fact, myopia is resulting from both genetic factors and environment factors as well as habits of using eyes. Genetic is not the only reason for myopia. I read an articles, There is 65% genetic possibility and 35% environmental possibility that cause myopia. From this point, myopia is genetic.
I don't believe that myopia is genetic. I think they are mostly because of the living environment and your life style as well as your habit. In my family, my parents have very good vision, so do my grandfather and grandmother, but i am still get myopia since i am in middle high school. So, myopia is not inherit from parents. And a study shows that people who like playing computer games are more likely suffer myopia. That is too say, your lifestyle is more important than genetic to get myopia.