How To Reduce The Cylindrical Power For My Son Whose

How to reduce the cylindrical power for my son whose age is just 3 years. He is having -2 in right eye and -2.75 left eye at 180degrees respectively. What can I do to reduce this eye sight. Should I do any changes in his feeding. How much time should he wear glasses daily. Why such a small kid gets eye sight. Can he watch the television and play with the mobile. Is there any exercise for eyes to improve the eye sight or is there any treatment or cylindrical eye sight.. please help me with your answer..
Thank you.