Hello doctor.I'm 19 this year and have a high myopia of −6.75(left eye)and −6.25(right eye) diopters.I do not want higher diopters.Is it fine to me if i play First Personal Shooting PC games(FPS) such as "medal of honor"or "counter strikes" only for a very limited time?(e.g.30mins per time,once a week)Is it still harmful to my eyes?Thank you !!!!!