Myopia in 5 year old kid

Well first thing we did when we discovered our 51/2 year old kid had some eye trouble was to go visit eye specialist. We didn't think he had short sight so when doctor said he has sight of -1 (6/9), we were shocked. We started thinking may be we didn't give him proper food, may be allowed too much TV or computer etc etc. But doctor said it is hereditary.
 Hereditary!!! how can this be hereditary? And based on the number of kids I am seeing daily now a days with spects, it cant be that Myopia has something to do with genes. Then came the online research part where some argue that root cause of myopia is too much stress on the eyes. This must be the case or else how can poor eye sight become hereditary suddenly. Some people claim that with proper eye exersices myopia can be reversed. And I know one of my relative who undergone the eye exersices treatment and got his myopia reversed from -7 to a state where he does not use glasses now.
When we asked the doctor, he said this is rubbish. He warned us not to browse internet regarding these things as they are only for academic purpose. He said it will keep on growing and it cannot be reversed.
So we decided there is nothing wrong in doing some eye exersices and we contacted the "School of perfect eyesight pondicherry" (http://sriaurobindoashram.info/Content.aspx?ContentURL=_staticcontent/sriaurobindoashram/-03%20the%20ashram/Departments/School%20For%20Perfect%20Eyesight/-00%20Contents.htm) and they said the kid has to be 7 years old for the eye exercises to be taught and to be effective. As per them, it is our choice as to whether we want to continue wearing spects or not but asked us to stop TV and Computer as much as possible and take our kid there when he is 7 years old.  This is a free service and we have to stay there in the school for one week for them to teach the eye exercises properly. So that's where we are right now. Waiting for our kid to be 7 years old before we visit pondicherry to do something about reversing the myopia.