Blurry vision causes?!

I haven't really been sleeping very much & drinking much water either, probally about two bottles worth in the past 3 days. Foodwise, I wake up too late for breakfist so I only have one meal a day, lunch. oddly when I look at something it's somewhat blurred, on the computer its even worse. I experimented with my older prescription & used eye drops and it improved, but overall its not as sharp as my current. I decided to see if I needed a new prescription and I was told my vision difference was very slight and wasnt worth the money unless I really wanted it... so I didnt. I use my computer 10+ hour's at a time, sometimes in the dark with full brightness on also, nearly forgot that part. Well now for example I got up to get parents downstairs & I felt slightly dizzy & vision blurred even worse Which only happens to me when I run for a longtime, etc.