Sir, Sometimes...In childhood, and Sometimes now when I wake Up suddenly after sitting too much time , i feel Dizzy type and Black colour .Eye sometimes and .Now is Reduced...But... Sometimes Notice i don't have blurred vision but I think and.sometimes without reason I feel...Head is heavy and this happen with me But 1.5 years ago i sitting on chair and Studies suddenly head Hit cycle handle..and after all normal but when I lie down and Start moving head on pillow I feel pain type on left portion where I may be hit...Ok..sir any serious plz reply ?