Suggest Treatment For Inability To Concentrate And Difficulty In Putting Letters

my son is 4 and a half yr old .he is unable to sit on one place more than 10 minute .he is unable to concentrate also. he easily forgets what has taught. he used to write the letters in a reverse order. difficulty in copying from board.. easily grasps thing whwn heard but difficult to write. having shortsight and astigmatism. underweight and underheight. always restless. is he hyperactive and dyslexia patient . how can we overcome this please help me