Hi .. If with your glasses , your vision is 20/20, then you do not have any problem in the eyes, just glass number. There is no need to be tensed. Myopia is a very common condition  Just wear the correct number for distance activities mainly. Keep it checking regularly. Maintain good lifestyle. As of now, glasses or contact lenses will do. As and when after 18 years and when number is stable, you can do laser to get rid of numbers.